Water is unsuitable for dousing fires involving electrical equipment due to several crucial reasons: 1. Conductivity Hazard: Water is an effective conductor of electricity. Its application on live electrical fires poses a grave risk of conducting electricity, potentially causing electrical shock orRead more
Water is unsuitable for dousing fires involving electrical equipment due to several crucial reasons:
1. Conductivity Hazard: Water is an effective conductor of electricity. Its application on live electrical fires poses a grave risk of conducting electricity, potentially causing electrical shock or short circuits, exacerbating the fire.
2. Electrocution Risk: Using water on live electrical sources increases the danger of electrocution for both firefighters and nearby individuals, posing a severe safety threat.
3. Equipment Damage: Water contact with live circuits can lead to irreparable damage to electrical equipment, resulting in equipment failure or further spread of the fire.
4. Effectiveness Concerns: Water might not effectively extinguish electrical fires as it fails to interrupt the electrical current or smother the fire adequately, allowing the fire to persist.
For electrical fires, employing non-conductive extinguishing agents like carbon dioxide or dry chemical extinguishers designed explicitly for electrical fires is imperative. This ensures the safety of individuals and prevents additional damage to the equipment involved.
LPG (liquefied petroleum gas) holds advantages over wood as a domestic fuel for several compelling reasons: 1. Cleaner Burning: LPG combustion is cleaner, emitting fewer pollutants like particulate matter and harmful gases, enhancing indoor air quality and reducing health risks compared to wood burnRead more
LPG (liquefied petroleum gas) holds advantages over wood as a domestic fuel for several compelling reasons:
1. Cleaner Burning: LPG combustion is cleaner, emitting fewer pollutants like particulate matter and harmful gases, enhancing indoor air quality and reducing health risks compared to wood burning.
2. Convenience and Accessibility: LPG is readily available, portable, and easier to control than wood. It eliminates the laborious tasks of wood gathering, chopping, and storage, making it more convenient for household heating and cooking needs.
3. Consistency and Dependability: LPG provides consistent heat without variations in quality or moisture content, ensuring a more dependable and constant energy source than wood.
4. Environmental Impact: Wood burning contributes to deforestation. LPG usage reduces this impact by minimizing the pressure on forests, curbing deforestation and forest degradation.
5. Safety Measures: LPG poses fewer safety hazards in terms of handling, storage, and combustion compared to wood stoves or open fires, thereby reducing the risks of accidents, burns, or carbon monoxide exposure.
6. Efficiency: LPG appliances often boast higher energy conversion efficiency than traditional wood-burning stoves, utilizing the fuel’s energy content more effectively.
Collectively, LPG emerges as a preferred domestic fuel over wood due to its cleanliness, convenience, reliability, reduced environmental impact, safety considerations, and higher efficiency in catering to household energy requirements.
Paper itself catches fire easily due to its combustible nature and low ignition temperature. However, when enveloping an aluminum pipe, it becomes less prone to ignition for several reasons: 1. Heat Conductivity: Aluminum is an exceptional heat conductor. Wrapping paper around the pipe enables efficRead more
Paper itself catches fire easily due to its combustible nature and low ignition temperature. However, when enveloping an aluminum pipe, it becomes less prone to ignition for several reasons:
1. Heat Conductivity: Aluminum is an exceptional heat conductor. Wrapping paper around the pipe enables efficient heat dissipation, preventing the paper from reaching the critical temperature required for combustion.
2. Insulating Barrier: The aluminum surface acts as a protective barrier between the paper and potential heat sources, minimizing direct contact with sparks or flames that could ignite the paper.
3. Oxygen Restriction: Tightly wrapping paper around the aluminum pipe can limit the availability of oxygen, a crucial element for combustion, hindering the paper’s ignition process.
4. Surface Modification: Altering the paper’s surface area and thickness by wrapping it around the pipe changes its susceptibility to immediate ignition by reducing exposure to external ignition sources.
5. Protective Shield: The aluminum pipe serves as a shield, shielding the paper from direct contact with heat sources, offering an added layer of protection against rapid combustion.
In essence, the aluminum pipe, by dissipating heat, providing insulation, restricting oxygen, altering surface features, and acting as a protective shield, significantly reduces the likelihood of the paper catching fire compared to when it is exposed independently.
The unit used to express the calorific value of a fuel is "joules per kilogram" (J/kg) or "kilojoules per kilogram" (kJ/kg) in the International System of Units (SI). Alternatively, in specific systems of measurement, it might be indicated in "calories per gram" (cal/g) or "kilocalories per gram" (kRead more
The unit used to express the calorific value of a fuel is “joules per kilogram” (J/kg) or “kilojoules per kilogram” (kJ/kg) in the International System of Units (SI). Alternatively, in specific systems of measurement, it might be indicated in “calories per gram” (cal/g) or “kilocalories per gram” (kcal/g).
Carbon dioxide (CO₂) effectively controls fires due to its specific properties: 1. Suffocation Effect: CO₂ displaces oxygen, forming a layer over the fire that suffocates it. By replacing oxygen with CO₂, the fire lacks the necessary oxygen concentration to sustain combustion. 2. Oxygen Reduction: CRead more
Carbon dioxide (CO₂) effectively controls fires due to its specific properties:
1. Suffocation Effect: CO₂ displaces oxygen, forming a layer over the fire that suffocates it. By replacing oxygen with CO₂, the fire lacks the necessary oxygen concentration to sustain combustion.
2. Oxygen Reduction: CO₂ lowers the surrounding oxygen levels, preventing the fire from maintaining the oxygen needed for continued burning, effectively halting the combustion process.
3. Cooling Properties: Upon discharge, CO₂ expands rapidly, absorbing heat and creating a cooling effect. This action reduces the temperature of the fuel and the fire’s surroundings, impeding the fire’s ability to sustain itself.
4. Chemical Interruption: CO₂ can interfere with the combustion chain reaction, disrupting the process necessary for the fire’s propagation, acting as a chemical inhibitor.
In summary, carbon dioxide extinguishes fires by smothering flames, reducing oxygen availability, cooling the area, and interrupting the combustion chain reaction, collectively halting the fire’s progression.
The difference in flammability between green and dry leaves is primarily due to their moisture content: 1. Moisture Content: Green leaves contain a higher moisture level, acting as a natural barrier against ignition. The moisture absorbs heat, making it difficult for the leaves to reach their ignitiRead more
The difference in flammability between green and dry leaves is primarily due to their moisture content:
1. Moisture Content: Green leaves contain a higher moisture level, acting as a natural barrier against ignition. The moisture absorbs heat, making it difficult for the leaves to reach their ignition temperature.
2. Ignition Temperature: Dry leaves, with lower moisture content, have a lower ignition temperature. They readily ignite as the absence of moisture reduces the energy required for combustion.
3. Heat Absorption: Moisture in green leaves absorbs heat during the initial burning stages, diverting it away from the leaves and impeding rapid temperature increase necessary for ignition.
4. Combustible Components: Dry leaves contain flammable components like cellulose and lignin, enabling rapid oxidation and easier combustion when dry.
In summary, the higher moisture content in green leaves hinders ignition by absorbing heat, while dry leaves, with lower moisture and combustible components, readily reach their ignition temperature, making them more prone to catching fire.
A goldsmith typically utilizes the innermost part of a flame, known as the "reducing zone" or "inner cone," for melting gold and silver due to specific advantages: 1. High Temperature: The inner cone boasts the highest temperatures within the flame structure, crucial for melting metals like gold andRead more
A goldsmith typically utilizes the innermost part of a flame, known as the “reducing zone” or “inner cone,” for melting gold and silver due to specific advantages:
1. High Temperature: The inner cone boasts the highest temperatures within the flame structure, crucial for melting metals like gold and silver with their high melting points.
2. Reducing Atmosphere: This zone maintains a lower oxygen concentration, creating an oxygen-deficient environment. This prevents oxidation or tarnishing of metals while melting, preserving their purity and luster.
3. Controlled Conditions: For precision in metalwork, goldsmiths need to control temperature and oxidation levels meticulously. The reducing zone’s high temperature and low oxygen environment allow for precise melting without compromising the metals’ integrity.
By harnessing the reducing zone of the flame, goldsmiths ensure the attainment of requisite high temperatures for melting gold and silver while safeguarding their purity, preventing oxidation or tarnishing, and enabling meticulous craftsmanship in creating jewelry or other precious metal articles.
1. Average speed = Total distance / Total time taken 2. Average velocity = Total displacement / Total time taken Let's start with the given information: - Joseph jogs from A to B, a distance of 300 meters, in 2 minutes 30 seconds. - Then, he turns around and jogs back 100 meters to point C in anotheRead more
1. Average speed = Total distance / Total time taken
2. Average velocity = Total displacement / Total time taken
Let’s start with the given information:
– Joseph jogs from A to B, a distance of 300 meters, in 2 minutes 30 seconds.
– Then, he turns around and jogs back 100 meters to point C in another 1 minute.
(a) Average Speed and Velocity from A to B:
1. Average Speed from A to B:
Speed = Total distance / Total time taken
Total distance from A to B = 300 meters
Total time taken from A to B = 2 minutes 30 seconds = 2.5 minutes
Speed = 300 meters / 2.5 minutes
Speed = 120 meters per minute
Therefore, Joseph’s average speed from A to B is 120 meters per minute.
2. Average Velocity from A to B:
As Joseph moves from A to B in a straight line, his displacement is the distance between the initial and final points.
Displacement from A to B = 300 meters (since he returns to the starting point, there’s no net displacement)
Total time taken from A to B = 2.5 minutes
Velocity = Displacement / Total time taken
Velocity = 300 meters / 2.5 minutes
Velocity = 120 meters per minute
Therefore, Joseph’s average velocity from A to B is 120 meters per minute.
(b) Average Speed and Velocity from A to C:
1. Average Speed from A to C:
Total distance from A to C = 300 meters + 100 meters = 400 meters
Total time taken from A to C = 2.5 minutes + 1 minute = 3.5 minutes
Speed = Total distance / Total time taken
Speed = 400 meters / 3.5 minutes
Speed ≈ 114.29 meters per minute
Therefore, Joseph’s average speed from A to C is approximately 114.29 meters per minute.
2. Average Velocity from A to C:
Joseph’s displacement from A to C accounts for the net distance covered in a straight line.
Displacement from A to C = 300 meters (distance from A to B) – 100 meters (distance from B to C)
Displacement from A to C = 200 meters (in the direction from A to C)
Total time taken from A to C = 3.5 minutes
Velocity = Displacement / Total time taken
Velocity = 200 meters / 3.5 minutes
Velocity ≈ 57.14 meters per minute
Therefore, Joseph’s average velocity from A to C is approximately 57.14 meters per minute.
Given: - Speed during the trip to school = 20 km/h - Speed during the return trip = 30 km/h To determine the overall average speed, we use the formula: Total average speed = Total distance / Total time Assuming Abdul travels the same distance to and from school: Calculation: Let's denote the distancRead more
Given:
– Speed during the trip to school = 20 km/h
– Speed during the return trip = 30 km/h
To determine the overall average speed, we use the formula:
Total average speed = Total distance / Total time
Assuming Abdul travels the same distance to and from school:
Calculation:
Let’s denote the distance to school as ‘D’.
– Time taken for the trip to school = Distance to school / Speed to school = D / 20
– Time taken for the return trip = Distance to school / Speed of return = D / 30
The total time for the entire trip:
Total time = Time to school + Time for return trip
Total time = D / 20 + D / 30
Now, the formula for total average speed:
Total average speed = Total distance / Total time
Substituting the expression for total time:
Total average speed = 2D / (D / 20 + D / 30)
Simplify the equation:
Total average speed = 2D / ((3D + 2D) / 60)
Total average speed = 2D / (5D / 60)
Total average speed = 120 / 5
Total average speed = 24 km/h
Hence, Abdul’s average speed for his entire round trip, accounting for both the journey to school and the return trip, is calculated to be 24 km/h. This indicates that considering his varying speeds in both directions, Abdul maintained an average speed of 24 km/h throughout the entire journey.
The distance traveled by the boat can be calculated using the kinematic equation: Distance = Initial velocity x time + 1/2 x acceleration x time^2 Given: - Initial velocity (u) = 0 m/s (starting from rest) - Acceleration (a) = 3.0 m/s² - Time (t) = 8.0 s Using the kinematic equation: Distance} = 0 xRead more
The distance traveled by the boat can be calculated using the kinematic equation:
Distance = Initial velocity x time + 1/2 x acceleration x time^2
Given:
– Initial velocity (u) = 0 m/s (starting from rest)
– Acceleration (a) = 3.0 m/s²
– Time (t) = 8.0 s
Using the kinematic equation:
Distance} = 0 x 8 + 1/2 x 3.0 x 8^2
Distance = 0 + 1/2 x 3.0 x 64
Distance = 1/2 x 192
Distance = 96
Therefore, the boat travels a distance of 96 meters during the 8.0 seconds of constant acceleration.
Give reasons: Water is not used to control fires involving electrical equipment.
Water is unsuitable for dousing fires involving electrical equipment due to several crucial reasons: 1. Conductivity Hazard: Water is an effective conductor of electricity. Its application on live electrical fires poses a grave risk of conducting electricity, potentially causing electrical shock orRead more
Water is unsuitable for dousing fires involving electrical equipment due to several crucial reasons:
1. Conductivity Hazard: Water is an effective conductor of electricity. Its application on live electrical fires poses a grave risk of conducting electricity, potentially causing electrical shock or short circuits, exacerbating the fire.
2. Electrocution Risk: Using water on live electrical sources increases the danger of electrocution for both firefighters and nearby individuals, posing a severe safety threat.
3. Equipment Damage: Water contact with live circuits can lead to irreparable damage to electrical equipment, resulting in equipment failure or further spread of the fire.
4. Effectiveness Concerns: Water might not effectively extinguish electrical fires as it fails to interrupt the electrical current or smother the fire adequately, allowing the fire to persist.
For electrical fires, employing non-conductive extinguishing agents like carbon dioxide or dry chemical extinguishers designed explicitly for electrical fires is imperative. This ensures the safety of individuals and prevents additional damage to the equipment involved.
See lessGive reasons: LPG is a better domestic fuel than wood.
LPG (liquefied petroleum gas) holds advantages over wood as a domestic fuel for several compelling reasons: 1. Cleaner Burning: LPG combustion is cleaner, emitting fewer pollutants like particulate matter and harmful gases, enhancing indoor air quality and reducing health risks compared to wood burnRead more
LPG (liquefied petroleum gas) holds advantages over wood as a domestic fuel for several compelling reasons:
1. Cleaner Burning: LPG combustion is cleaner, emitting fewer pollutants like particulate matter and harmful gases, enhancing indoor air quality and reducing health risks compared to wood burning.
2. Convenience and Accessibility: LPG is readily available, portable, and easier to control than wood. It eliminates the laborious tasks of wood gathering, chopping, and storage, making it more convenient for household heating and cooking needs.
3. Consistency and Dependability: LPG provides consistent heat without variations in quality or moisture content, ensuring a more dependable and constant energy source than wood.
4. Environmental Impact: Wood burning contributes to deforestation. LPG usage reduces this impact by minimizing the pressure on forests, curbing deforestation and forest degradation.
5. Safety Measures: LPG poses fewer safety hazards in terms of handling, storage, and combustion compared to wood stoves or open fires, thereby reducing the risks of accidents, burns, or carbon monoxide exposure.
6. Efficiency: LPG appliances often boast higher energy conversion efficiency than traditional wood-burning stoves, utilizing the fuel’s energy content more effectively.
Collectively, LPG emerges as a preferred domestic fuel over wood due to its cleanliness, convenience, reliability, reduced environmental impact, safety considerations, and higher efficiency in catering to household energy requirements.
See lessGive reasons: Paper by itself catches fire easily whereas a piece of paper wrapped around an aluminum pipe does not.
Paper itself catches fire easily due to its combustible nature and low ignition temperature. However, when enveloping an aluminum pipe, it becomes less prone to ignition for several reasons: 1. Heat Conductivity: Aluminum is an exceptional heat conductor. Wrapping paper around the pipe enables efficRead more
Paper itself catches fire easily due to its combustible nature and low ignition temperature. However, when enveloping an aluminum pipe, it becomes less prone to ignition for several reasons:
1. Heat Conductivity: Aluminum is an exceptional heat conductor. Wrapping paper around the pipe enables efficient heat dissipation, preventing the paper from reaching the critical temperature required for combustion.
2. Insulating Barrier: The aluminum surface acts as a protective barrier between the paper and potential heat sources, minimizing direct contact with sparks or flames that could ignite the paper.
3. Oxygen Restriction: Tightly wrapping paper around the aluminum pipe can limit the availability of oxygen, a crucial element for combustion, hindering the paper’s ignition process.
4. Surface Modification: Altering the paper’s surface area and thickness by wrapping it around the pipe changes its susceptibility to immediate ignition by reducing exposure to external ignition sources.
5. Protective Shield: The aluminum pipe serves as a shield, shielding the paper from direct contact with heat sources, offering an added layer of protection against rapid combustion.
In essence, the aluminum pipe, by dissipating heat, providing insulation, restricting oxygen, altering surface features, and acting as a protective shield, significantly reduces the likelihood of the paper catching fire compared to when it is exposed independently.
See lessName the unit in which the calorific value of a fuel is expressed.
The unit used to express the calorific value of a fuel is "joules per kilogram" (J/kg) or "kilojoules per kilogram" (kJ/kg) in the International System of Units (SI). Alternatively, in specific systems of measurement, it might be indicated in "calories per gram" (cal/g) or "kilocalories per gram" (kRead more
The unit used to express the calorific value of a fuel is “joules per kilogram” (J/kg) or “kilojoules per kilogram” (kJ/kg) in the International System of Units (SI). Alternatively, in specific systems of measurement, it might be indicated in “calories per gram” (cal/g) or “kilocalories per gram” (kcal/g).
See lessExplain how CO₂ is able to control fires.
Carbon dioxide (CO₂) effectively controls fires due to its specific properties: 1. Suffocation Effect: CO₂ displaces oxygen, forming a layer over the fire that suffocates it. By replacing oxygen with CO₂, the fire lacks the necessary oxygen concentration to sustain combustion. 2. Oxygen Reduction: CRead more
Carbon dioxide (CO₂) effectively controls fires due to its specific properties:
1. Suffocation Effect: CO₂ displaces oxygen, forming a layer over the fire that suffocates it. By replacing oxygen with CO₂, the fire lacks the necessary oxygen concentration to sustain combustion.
2. Oxygen Reduction: CO₂ lowers the surrounding oxygen levels, preventing the fire from maintaining the oxygen needed for continued burning, effectively halting the combustion process.
3. Cooling Properties: Upon discharge, CO₂ expands rapidly, absorbing heat and creating a cooling effect. This action reduces the temperature of the fuel and the fire’s surroundings, impeding the fire’s ability to sustain itself.
4. Chemical Interruption: CO₂ can interfere with the combustion chain reaction, disrupting the process necessary for the fire’s propagation, acting as a chemical inhibitor.
In summary, carbon dioxide extinguishes fires by smothering flames, reducing oxygen availability, cooling the area, and interrupting the combustion chain reaction, collectively halting the fire’s progression.
See lessIt is difficult to burn a heap of green leaves but dry leaves catch fire easily. Explain.
The difference in flammability between green and dry leaves is primarily due to their moisture content: 1. Moisture Content: Green leaves contain a higher moisture level, acting as a natural barrier against ignition. The moisture absorbs heat, making it difficult for the leaves to reach their ignitiRead more
The difference in flammability between green and dry leaves is primarily due to their moisture content:
1. Moisture Content: Green leaves contain a higher moisture level, acting as a natural barrier against ignition. The moisture absorbs heat, making it difficult for the leaves to reach their ignition temperature.
2. Ignition Temperature: Dry leaves, with lower moisture content, have a lower ignition temperature. They readily ignite as the absence of moisture reduces the energy required for combustion.
3. Heat Absorption: Moisture in green leaves absorbs heat during the initial burning stages, diverting it away from the leaves and impeding rapid temperature increase necessary for ignition.
4. Combustible Components: Dry leaves contain flammable components like cellulose and lignin, enabling rapid oxidation and easier combustion when dry.
In summary, the higher moisture content in green leaves hinders ignition by absorbing heat, while dry leaves, with lower moisture and combustible components, readily reach their ignition temperature, making them more prone to catching fire.
See lessWhich zone of a flame does a goldsmith use for melting gold and silver and why?
A goldsmith typically utilizes the innermost part of a flame, known as the "reducing zone" or "inner cone," for melting gold and silver due to specific advantages: 1. High Temperature: The inner cone boasts the highest temperatures within the flame structure, crucial for melting metals like gold andRead more
A goldsmith typically utilizes the innermost part of a flame, known as the “reducing zone” or “inner cone,” for melting gold and silver due to specific advantages:
1. High Temperature: The inner cone boasts the highest temperatures within the flame structure, crucial for melting metals like gold and silver with their high melting points.
2. Reducing Atmosphere: This zone maintains a lower oxygen concentration, creating an oxygen-deficient environment. This prevents oxidation or tarnishing of metals while melting, preserving their purity and luster.
3. Controlled Conditions: For precision in metalwork, goldsmiths need to control temperature and oxidation levels meticulously. The reducing zone’s high temperature and low oxygen environment allow for precise melting without compromising the metals’ integrity.
By harnessing the reducing zone of the flame, goldsmiths ensure the attainment of requisite high temperatures for melting gold and silver while safeguarding their purity, preventing oxidation or tarnishing, and enabling meticulous craftsmanship in creating jewelry or other precious metal articles.
See lessJoseph jogs from one end A to the other end B of a straight 300 m road in 2 minutes 50 seconds and then turns around and jogs 100 m back to point C in another 1 minute. What are Joseph’s average speeds and velocities in jogging (a) from A to B and (b) from A to C?
1. Average speed = Total distance / Total time taken 2. Average velocity = Total displacement / Total time taken Let's start with the given information: - Joseph jogs from A to B, a distance of 300 meters, in 2 minutes 30 seconds. - Then, he turns around and jogs back 100 meters to point C in anotheRead more
1. Average speed = Total distance / Total time taken
2. Average velocity = Total displacement / Total time taken
Let’s start with the given information:
– Joseph jogs from A to B, a distance of 300 meters, in 2 minutes 30 seconds.
– Then, he turns around and jogs back 100 meters to point C in another 1 minute.
(a) Average Speed and Velocity from A to B:
1. Average Speed from A to B:
Speed = Total distance / Total time taken
Total distance from A to B = 300 meters
Total time taken from A to B = 2 minutes 30 seconds = 2.5 minutes
Speed = 300 meters / 2.5 minutes
Speed = 120 meters per minute
Therefore, Joseph’s average speed from A to B is 120 meters per minute.
2. Average Velocity from A to B:
As Joseph moves from A to B in a straight line, his displacement is the distance between the initial and final points.
Displacement from A to B = 300 meters (since he returns to the starting point, there’s no net displacement)
Total time taken from A to B = 2.5 minutes
Velocity = Displacement / Total time taken
Velocity = 300 meters / 2.5 minutes
Velocity = 120 meters per minute
Therefore, Joseph’s average velocity from A to B is 120 meters per minute.
(b) Average Speed and Velocity from A to C:
1. Average Speed from A to C:
Total distance from A to C = 300 meters + 100 meters = 400 meters
Total time taken from A to C = 2.5 minutes + 1 minute = 3.5 minutes
Speed = Total distance / Total time taken
Speed = 400 meters / 3.5 minutes
Speed ≈ 114.29 meters per minute
Therefore, Joseph’s average speed from A to C is approximately 114.29 meters per minute.
2. Average Velocity from A to C:
Joseph’s displacement from A to C accounts for the net distance covered in a straight line.
Displacement from A to C = 300 meters (distance from A to B) – 100 meters (distance from B to C)
Displacement from A to C = 200 meters (in the direction from A to C)
Total time taken from A to C = 3.5 minutes
Velocity = Displacement / Total time taken
See lessVelocity = 200 meters / 3.5 minutes
Velocity ≈ 57.14 meters per minute
Therefore, Joseph’s average velocity from A to C is approximately 57.14 meters per minute.
Abdul, while driving to school, computes the average speed for his trip to be 20 km/h. On his return trip along the same route, there is less traffic and the average speed is 30 km /h. What is the average speed for Abdul’s trip?
Given: - Speed during the trip to school = 20 km/h - Speed during the return trip = 30 km/h To determine the overall average speed, we use the formula: Total average speed = Total distance / Total time Assuming Abdul travels the same distance to and from school: Calculation: Let's denote the distancRead more
Given:
– Speed during the trip to school = 20 km/h
– Speed during the return trip = 30 km/h
To determine the overall average speed, we use the formula:
Total average speed = Total distance / Total time
Assuming Abdul travels the same distance to and from school:
Calculation:
Let’s denote the distance to school as ‘D’.
– Time taken for the trip to school = Distance to school / Speed to school = D / 20
– Time taken for the return trip = Distance to school / Speed of return = D / 30
The total time for the entire trip:
Total time = Time to school + Time for return trip
Total time = D / 20 + D / 30
Now, the formula for total average speed:
Total average speed = Total distance / Total time
Substituting the expression for total time:
Total average speed = 2D / (D / 20 + D / 30)
Simplify the equation:
Total average speed = 2D / ((3D + 2D) / 60)
Total average speed = 2D / (5D / 60)
Total average speed = 120 / 5
Total average speed = 24 km/h
Hence, Abdul’s average speed for his entire round trip, accounting for both the journey to school and the return trip, is calculated to be 24 km/h. This indicates that considering his varying speeds in both directions, Abdul maintained an average speed of 24 km/h throughout the entire journey.
See lessA motorboat starting from rest on a lake accelerates in a straight line at a constant rate of 3.0 m s–2 for 8.0 s. How far does the boat travel during this time?
The distance traveled by the boat can be calculated using the kinematic equation: Distance = Initial velocity x time + 1/2 x acceleration x time^2 Given: - Initial velocity (u) = 0 m/s (starting from rest) - Acceleration (a) = 3.0 m/s² - Time (t) = 8.0 s Using the kinematic equation: Distance} = 0 xRead more
The distance traveled by the boat can be calculated using the kinematic equation:
Distance = Initial velocity x time + 1/2 x acceleration x time^2
Given:
– Initial velocity (u) = 0 m/s (starting from rest)
– Acceleration (a) = 3.0 m/s²
– Time (t) = 8.0 s
Using the kinematic equation:
Distance} = 0 x 8 + 1/2 x 3.0 x 8^2
Distance = 0 + 1/2 x 3.0 x 64
Distance = 1/2 x 192
Distance = 96
Therefore, the boat travels a distance of 96 meters during the 8.0 seconds of constant acceleration.
See less