The crackling sound while removing a sweater in winter results from static electricity buildup: 1. Static Electricity Generation: In cold, dry conditions, materials like wool or synthetics create static electricity due to friction. When you wear a sweater, friction between it and your clothes or skiRead more
The crackling sound while removing a sweater in winter results from static electricity buildup:
1. Static Electricity Generation: In cold, dry conditions, materials like wool or synthetics create static electricity due to friction. When you wear a sweater, friction between it and your clothes or skin generates a static charge.
2. Electron Transfer: Rubbing between materials causes electron transfer, leading to an imbalance in electrical charges on the surfaces involved.
3. Electrostatic Discharge: Removing the sweater causes the accumulated static charge to discharge suddenly. This discharge produces a crackling sound and sometimes a small spark as electrons move to balance the charges.
4. Dry Air’s Impact: Winter’s dry air exacerbates static buildup since moisture in the air aids in charge dissipation. Dry conditions intensify static charge accumulation, leading to noticeable crackling.
To mitigate static buildup, use moisturizers to slightly increase humidity, avoid clothing prone to static, or use antistatic sprays or dryer sheets to reduce static cling in fabrics.
When a candle is placed between two parallel plane mirrors, multiple images can be formed due to the phenomenon of multiple reflections. The number of images formed can be calculated using the formula: Number of Images = 360°/(angle between mirrors - 360°) For parallel mirrors, the angle between theRead more
When a candle is placed between two parallel plane mirrors, multiple images can be formed due to the phenomenon of multiple reflections. The number of images formed can be calculated using the formula:
Number of Images = 360°/(angle between mirrors – 360°)
For parallel mirrors, the angle between the mirrors is twice the angle formed between one of the mirrors and the line perpendicular to them.
Given that the distance between the mirrors is 40 cm, and they are parallel, we need to find the angle between the mirrors. Using trigonometry:
tan θ = (distance between mirrors)/(length of mirror)
tan θ = (40 cm)/(length of mirror)
θ = tan⁻¹ ((40cm)/(length of mirror))
The angle between the mirrors (and consequently the angle of each image) depends on the length of the mirror, which is not specified. Without the specific length of the mirrors, the exact number of images formed cannot be determined.
However, in theory, for an infinite length of mirrors and an angle between them calculated from the given distance, an infinite number of images would be formed. In practical scenarios with finite mirrors, the number of images formed would be significantly large but finite.
1. Newton's First Law - Law of Inertia: - Objects at rest remain at rest, and objects in motion continue in uniform motion unless acted upon by an external force. This principle is known as Newton's first law of motion. 2. State of Rest or Motion: - An object at rest will not experience any displaceRead more
1. Newton’s First Law – Law of Inertia:
– Objects at rest remain at rest, and objects in motion continue in uniform motion unless acted upon by an external force. This principle is known as Newton’s first law of motion.
2. State of Rest or Motion:
– An object at rest will not experience any displacement in the absence of an external force. It remains stationary due to its inherent property called inertia.
– If an object is already in motion without any external force acting on it, it will continue moving at a constant velocity in a straight line without experiencing any change in displacement.
3. Role of Inertia:
– Inertia is the tendency of an object to resist changes in its state of motion. It allows objects to maintain their current state unless influenced by an external force.
– In the absence of forces, inertia enables an object to continue its state of rest or motion without any change in displacement.
4. Examples Illustrating Displacement Without External Force:
– A hockey puck sliding on an ice rink will continue gliding in the absence of friction or external forces, demonstrating displacement due to inertia once set in motion.
– Consider a satellite orbiting in space. In the vacuum of space with negligible resistance, the satellite follows its path without any external force, experiencing displacement due to inertia.
5. Natural Phenomena and Inertia:
– Celestial bodies such as planets and moons can move in space due to their inertia and the absence of significant external forces, showing displacement without an applied force.
6. Discussion Point:
– The concept challenges the common perception that every movement requires a force. It highlights the significance of inertia in governing an object’s behavior when no external forces act upon it.
Understanding these points based on Newton’s first law provides insights into the role of inertia in allowing displacement of objects in the absence of external forces, encouraging discussions on the fundamental nature of motion and forces.
1. Definition of Work in Physics: - Work is defined as the product of force and displacement in the direction of the force applied. 2. Force Exerted by the Person: - The person exerts a force against gravity to hold the bundle of hay over his head, countering the weight of the hay. 3. Absence of DisRead more
1. Definition of Work in Physics:
– Work is defined as the product of force and displacement in the direction of the force applied.
2. Force Exerted by the Person:
– The person exerts a force against gravity to hold the bundle of hay over his head, countering the weight of the hay.
3. Absence of Displacement:
– Despite exerting a force to hold the bundle, there is no vertical displacement or change in the position of the hay during the 30 minutes.
– The bundle of hay remains stationary and does not move vertically while being held.
4. Work Calculation Criteria:
– For work to be done, there must be a displacement in the direction of the force applied.
– Work is calculated as W = F x d x cos(θ), where F is force, (d) is displacement, and (θ) is the angle between force and displacement.
5. No Displacement, No Work Done:
– In this scenario, although the person exerts a force to counteract gravity, there is no vertical movement or displacement of the hay.
– The absence of vertical displacement means that the force applied by the person does not result in any work being done on the bundle of hay.
6. Explanation of Fatigue:
– The person may feel tired due to muscular effort expended to maintain the position of the hay against gravity for an extended period.
– However, the fatigue is not due to the performance of physical work in the physics sense as there is no displacement in the direction of the force applied.
1. Power Rating of the Electric Heater: - The power rating of the electric heater is 1500 watts (W). 2. Time Duration: - The time duration for which we want to calculate the energy used is 10 hours. 3. Formula for Energy Calculation: - The formula to calculate energy (in joules) is: Energy = Power ×Read more
1. Power Rating of the Electric Heater:
– The power rating of the electric heater is 1500 watts (W).
2. Time Duration:
– The time duration for which we want to calculate the energy used is 10 hours.
3. Formula for Energy Calculation:
– The formula to calculate energy (in joules) is: Energy = Power × Time
4. Conversion of Time:
– Convert the time duration from hours to seconds because the power is given in watts.
– 10 hours = 10 x 60 x 60 seconds = 36,000 seconds
5. Calculation of Energy Used:
– Energy Used = Power × Time
– Energy Used = 1500 W x 36,000 s
– Energy Used = 54,000,000 J
6. Conversion to Kilowatt-Hours (Optional):
– To express energy in kilowatt-hours (kWh), divide the energy in joules by 3.6 x 10⁶ (since 1 kWh = 3.6 x 10⁶ J).
– Energy Used in kWh = (54,000,000 J)/(3.6 x 10⁶ J/kWh)
– Energy Used in kWh = 15 kWh
Therefore, the electric heater rated at 1500 W will consume 54,000,000 joules of energy or 15 kilowatt-hours of energy in 10 hours of operation.
Sometimes, a crackling sound is heard while taking off a sweater during winters. Explain.
The crackling sound while removing a sweater in winter results from static electricity buildup: 1. Static Electricity Generation: In cold, dry conditions, materials like wool or synthetics create static electricity due to friction. When you wear a sweater, friction between it and your clothes or skiRead more
The crackling sound while removing a sweater in winter results from static electricity buildup:
1. Static Electricity Generation: In cold, dry conditions, materials like wool or synthetics create static electricity due to friction. When you wear a sweater, friction between it and your clothes or skin generates a static charge.
2. Electron Transfer: Rubbing between materials causes electron transfer, leading to an imbalance in electrical charges on the surfaces involved.
3. Electrostatic Discharge: Removing the sweater causes the accumulated static charge to discharge suddenly. This discharge produces a crackling sound and sometimes a small spark as electrons move to balance the charges.
4. Dry Air’s Impact: Winter’s dry air exacerbates static buildup since moisture in the air aids in charge dissipation. Dry conditions intensify static charge accumulation, leading to noticeable crackling.
To mitigate static buildup, use moisturizers to slightly increase humidity, avoid clothing prone to static, or use antistatic sprays or dryer sheets to reduce static cling in fabrics.
See lessHow many images of a candle will be formed if it is placed between two parallel plane mirrors separated by 40 cm?
When a candle is placed between two parallel plane mirrors, multiple images can be formed due to the phenomenon of multiple reflections. The number of images formed can be calculated using the formula: Number of Images = 360°/(angle between mirrors - 360°) For parallel mirrors, the angle between theRead more
When a candle is placed between two parallel plane mirrors, multiple images can be formed due to the phenomenon of multiple reflections. The number of images formed can be calculated using the formula:
Number of Images = 360°/(angle between mirrors – 360°)
For parallel mirrors, the angle between the mirrors is twice the angle formed between one of the mirrors and the line perpendicular to them.
Given that the distance between the mirrors is 40 cm, and they are parallel, we need to find the angle between the mirrors. Using trigonometry:
tan θ = (distance between mirrors)/(length of mirror)
tan θ = (40 cm)/(length of mirror)
θ = tan⁻¹ ((40cm)/(length of mirror))
The angle between the mirrors (and consequently the angle of each image) depends on the length of the mirror, which is not specified. Without the specific length of the mirrors, the exact number of images formed cannot be determined.
However, in theory, for an infinite length of mirrors and an angle between them calculated from the given distance, an infinite number of images would be formed. In practical scenarios with finite mirrors, the number of images formed would be significantly large but finite.
See lessCan there be displacement of an object in the absence of any force acting on it? Think. Discuss this question with your friends and teacher.
1. Newton's First Law - Law of Inertia: - Objects at rest remain at rest, and objects in motion continue in uniform motion unless acted upon by an external force. This principle is known as Newton's first law of motion. 2. State of Rest or Motion: - An object at rest will not experience any displaceRead more
1. Newton’s First Law – Law of Inertia:
– Objects at rest remain at rest, and objects in motion continue in uniform motion unless acted upon by an external force. This principle is known as Newton’s first law of motion.
2. State of Rest or Motion:
– An object at rest will not experience any displacement in the absence of an external force. It remains stationary due to its inherent property called inertia.
– If an object is already in motion without any external force acting on it, it will continue moving at a constant velocity in a straight line without experiencing any change in displacement.
3. Role of Inertia:
– Inertia is the tendency of an object to resist changes in its state of motion. It allows objects to maintain their current state unless influenced by an external force.
– In the absence of forces, inertia enables an object to continue its state of rest or motion without any change in displacement.
4. Examples Illustrating Displacement Without External Force:
– A hockey puck sliding on an ice rink will continue gliding in the absence of friction or external forces, demonstrating displacement due to inertia once set in motion.
– Consider a satellite orbiting in space. In the vacuum of space with negligible resistance, the satellite follows its path without any external force, experiencing displacement due to inertia.
5. Natural Phenomena and Inertia:
– Celestial bodies such as planets and moons can move in space due to their inertia and the absence of significant external forces, showing displacement without an applied force.
6. Discussion Point:
– The concept challenges the common perception that every movement requires a force. It highlights the significance of inertia in governing an object’s behavior when no external forces act upon it.
Understanding these points based on Newton’s first law provides insights into the role of inertia in allowing displacement of objects in the absence of external forces, encouraging discussions on the fundamental nature of motion and forces.
See lessA person holds a bundle of hay over his head for 30 minutes and gets tired. Has he done some work or not? Justify your answer.
1. Definition of Work in Physics: - Work is defined as the product of force and displacement in the direction of the force applied. 2. Force Exerted by the Person: - The person exerts a force against gravity to hold the bundle of hay over his head, countering the weight of the hay. 3. Absence of DisRead more
1. Definition of Work in Physics:
– Work is defined as the product of force and displacement in the direction of the force applied.
2. Force Exerted by the Person:
– The person exerts a force against gravity to hold the bundle of hay over his head, countering the weight of the hay.
3. Absence of Displacement:
– Despite exerting a force to hold the bundle, there is no vertical displacement or change in the position of the hay during the 30 minutes.
– The bundle of hay remains stationary and does not move vertically while being held.
4. Work Calculation Criteria:
– For work to be done, there must be a displacement in the direction of the force applied.
– Work is calculated as W = F x d x cos(θ), where F is force, (d) is displacement, and (θ) is the angle between force and displacement.
5. No Displacement, No Work Done:
– In this scenario, although the person exerts a force to counteract gravity, there is no vertical movement or displacement of the hay.
– The absence of vertical displacement means that the force applied by the person does not result in any work being done on the bundle of hay.
6. Explanation of Fatigue:
See less– The person may feel tired due to muscular effort expended to maintain the position of the hay against gravity for an extended period.
– However, the fatigue is not due to the performance of physical work in the physics sense as there is no displacement in the direction of the force applied.
An electric heater is rated 1500 W. How much energy does it use in 10 hours?
1. Power Rating of the Electric Heater: - The power rating of the electric heater is 1500 watts (W). 2. Time Duration: - The time duration for which we want to calculate the energy used is 10 hours. 3. Formula for Energy Calculation: - The formula to calculate energy (in joules) is: Energy = Power ×Read more
1. Power Rating of the Electric Heater:
– The power rating of the electric heater is 1500 watts (W).
2. Time Duration:
– The time duration for which we want to calculate the energy used is 10 hours.
3. Formula for Energy Calculation:
– The formula to calculate energy (in joules) is: Energy = Power × Time
4. Conversion of Time:
– Convert the time duration from hours to seconds because the power is given in watts.
– 10 hours = 10 x 60 x 60 seconds = 36,000 seconds
5. Calculation of Energy Used:
– Energy Used = Power × Time
– Energy Used = 1500 W x 36,000 s
– Energy Used = 54,000,000 J
6. Conversion to Kilowatt-Hours (Optional):
– To express energy in kilowatt-hours (kWh), divide the energy in joules by 3.6 x 10⁶ (since 1 kWh = 3.6 x 10⁶ J).
– Energy Used in kWh = (54,000,000 J)/(3.6 x 10⁶ J/kWh)
– Energy Used in kWh = 15 kWh
Therefore, the electric heater rated at 1500 W will consume 54,000,000 joules of energy or 15 kilowatt-hours of energy in 10 hours of operation.
See less