In (i), potential energy gain equals m g h, which is 50 kg multiplied by 10 m s-2 multiplied by 72.5 m, yielding 36250 J. In (ii), climbing the stairs reaches the same vertical elevation, giving an identical gain of 36250 J. In (iii), we conclude that gravitational potential energy depends solely onRead more
In (i), potential energy gain equals m g h, which is 50 kg multiplied by 10 m s-2 multiplied by 72.5 m, yielding 36250 J. In (ii), climbing the stairs reaches the same vertical elevation, giving an identical gain of 36250 J. In (iii), we conclude that gravitational potential energy depends solely on initial and final vertical positions, being independent of the path followed.
For more NCERT Solutions of Class 9 Science Exploration Chapter 7 Work, Energy and Simple Machines Question Answer (2026-27)
Reaching the 20th floor doubles the vertical displacement compared to the 10th floor, so the required energy m g h doubles, requiring one hundred percent more energy. Power is work divided by time. Because both work and time double simultaneously, the ratio of work to time remains constant. ThereforRead more
Reaching the 20th floor doubles the vertical displacement compared to the 10th floor, so the required energy m g h doubles, requiring one hundred percent more energy. Power is work divided by time. Because both work and time double simultaneously, the ratio of work to time remains constant. Therefore, no additional power is required and the power required remains the same.
For more NCERT Solutions of Class 9 Science Exploration Chapter 7 Work, Energy and Simple Machines Question Answer (2026-27)
The energy required is determined by the mass of the flag, acceleration due to gravity and vertical height of the flagpole. The work done equals m g h and remains independent of speed or time. However, doubling the speed cuts the time taken in half. Since power is work divided by time, halving the tRead more
The energy required is determined by the mass of the flag, acceleration due to gravity and vertical height of the flagpole. The work done equals m g h and remains independent of speed or time. However, doubling the speed cuts the time taken in half. Since power is work divided by time, halving the time doubles the power requirement.
For more NCERT Solutions of Class 9 Science Exploration Chapter 7 Work, Energy and Simple Machines Question Answer (2026-27)
Total balls = 4 Red + 5 Blue = 9. Since the first ball is not replaced, 8 balls remain for the second pick. Tree diagram paths: First branch splits into Red (4/9) and Blue (5/9). From Red, second branches split into Red (3/8) and Blue (5/8). From Blue, second branches split into Red (4/8) and Blue (Read more
Total balls = 4 Red + 5 Blue = 9. Since the first ball is not replaced, 8 balls remain for the second pick.
Tree diagram paths:
First branch splits into Red (4/9) and Blue (5/9).
From Red, second branches split into Red (3/8) and Blue (5/8).
From Blue, second branches split into Red (4/8) and Blue (4/8).
(i) P(Red then Blue) = (4/9) x (5/8) = 20/72 = 5/18 (approx 0.278).
(ii) P(2 Blue balls) = (5/9) x (4/8) = 20/72 = 5/18 (approx 0.278).
For more NCERT Solutions of Class 9 Ganita Manjari Chapter 7 The Mathematics of Maybe: Introduction to Probability Question Answer (2026-27)
A student is slowly lifted straight up in an elevator from the ground level to the top floor of a building. Later, the same student climbs the staircase, all the way to the top. Given that the height of the building is h = 72.5 m, acceleration due to gravity is g = 10 m s-2 and student’s mass is m = 50 kg. (i) Find the gain in the potential energy if the student is lifted straight up to the top. (ii) Find the gain in the potential energy when the student climbs the stairs to the same top. (iii) What do you conclude about the dependence of the potential energy on the path taken?
In (i), potential energy gain equals m g h, which is 50 kg multiplied by 10 m s-2 multiplied by 72.5 m, yielding 36250 J. In (ii), climbing the stairs reaches the same vertical elevation, giving an identical gain of 36250 J. In (iii), we conclude that gravitational potential energy depends solely onRead more
In (i), potential energy gain equals m g h, which is 50 kg multiplied by 10 m s-2 multiplied by 72.5 m, yielding 36250 J. In (ii), climbing the stairs reaches the same vertical elevation, giving an identical gain of 36250 J. In (iii), we conclude that gravitational potential energy depends solely on initial and final vertical positions, being independent of the path followed.
For more NCERT Solutions of Class 9 Science Exploration Chapter 7 Work, Energy and Simple Machines Question Answer (2026-27)
https://www.tiwariacademy.com/ncert-solutions/class-9/science/exploration-chapter-7/
See lessA crane lifts a mass m to the 10th floor of a building in a certain time. It then raises the same mass to the 20th floor of the same building in double the time. How much more energy and power are required? Assume that the height of all floors is equal.
Reaching the 20th floor doubles the vertical displacement compared to the 10th floor, so the required energy m g h doubles, requiring one hundred percent more energy. Power is work divided by time. Because both work and time double simultaneously, the ratio of work to time remains constant. ThereforRead more
Reaching the 20th floor doubles the vertical displacement compared to the 10th floor, so the required energy m g h doubles, requiring one hundred percent more energy. Power is work divided by time. Because both work and time double simultaneously, the ratio of work to time remains constant. Therefore, no additional power is required and the power required remains the same.
For more NCERT Solutions of Class 9 Science Exploration Chapter 7 Work, Energy and Simple Machines Question Answer (2026-27)
https://www.tiwariacademy.com/ncert-solutions/class-9/science/exploration-chapter-7/
See lessWhich factors determine the energy required to raise a flag from the ground to the top of a tall flagpole using a pulley? Does raising the flag slowly or quickly change the amount of work done? If the speed at which the flag is raised is doubled, how does the power requirement change? Explain your answers.
The energy required is determined by the mass of the flag, acceleration due to gravity and vertical height of the flagpole. The work done equals m g h and remains independent of speed or time. However, doubling the speed cuts the time taken in half. Since power is work divided by time, halving the tRead more
The energy required is determined by the mass of the flag, acceleration due to gravity and vertical height of the flagpole. The work done equals m g h and remains independent of speed or time. However, doubling the speed cuts the time taken in half. Since power is work divided by time, halving the time doubles the power requirement.
For more NCERT Solutions of Class 9 Science Exploration Chapter 7 Work, Energy and Simple Machines Question Answer (2026-27)
https://www.tiwariacademy.com/ncert-solutions/class-9/science/exploration-chapter-7/
See lessA basket contains 4 red balls and 5 blue balls. One ball is drawn and laid aside and a second ball is drawn. Draw a tree diagram to represent the possible outcomes and probabilities. Use the tree diagram to answer the following questions: (i) What is the probability of drawing a red ball and then a blue ball? (ii) What is the probability of drawing 2 blue balls?
Total balls = 4 Red + 5 Blue = 9. Since the first ball is not replaced, 8 balls remain for the second pick. Tree diagram paths: First branch splits into Red (4/9) and Blue (5/9). From Red, second branches split into Red (3/8) and Blue (5/8). From Blue, second branches split into Red (4/8) and Blue (Read more
Total balls = 4 Red + 5 Blue = 9. Since the first ball is not replaced, 8 balls remain for the second pick.
Tree diagram paths:
First branch splits into Red (4/9) and Blue (5/9).
From Red, second branches split into Red (3/8) and Blue (5/8).
From Blue, second branches split into Red (4/8) and Blue (4/8).
(i) P(Red then Blue) = (4/9) x (5/8) = 20/72 = 5/18 (approx 0.278).
(ii) P(2 Blue balls) = (5/9) x (4/8) = 20/72 = 5/18 (approx 0.278).
For more NCERT Solutions of Class 9 Ganita Manjari Chapter 7 The Mathematics of Maybe: Introduction to Probability Question Answer (2026-27)
https://www.tiwariacademy.com/ncert-solutions/class-9/maths/ganita-manjari-chapter-7/
See lessA game of chance consists of spinning an arrow (see Fig. 7.7.) which comes to rest pointing at one of the numbers 1, 2, 3, 4, 5, 6, 7, 8 and these are equally likely outcomes. What is the probability that it will point at: (i) 8? (ii) An odd number? (iii) A number greater than 2? (iv) A number less than 9? (v) A multiple of 3?
Total possible outcomes = 8, as the arrow can point to {1, 2, 3, 4, 5, 6, 7, 8}. (i) Favourable outcome = {8}. Probability = 1/8 = 0.125. (ii) Odd numbers = {1, 3, 5, 7}. Probability = 4/8 = 1/2 = 0.5. (iii) Numbers greater than 2 = {3, 4, 5, 6, 7, 8}. Probability = 6/8 = 3/4 = 0.75. (iv) Numbers leRead more
Total possible outcomes = 8, as the arrow can point to {1, 2, 3, 4, 5, 6, 7, 8}.
(i) Favourable outcome = {8}. Probability = 1/8 = 0.125.
(ii) Odd numbers = {1, 3, 5, 7}. Probability = 4/8 = 1/2 = 0.5.
(iii) Numbers greater than 2 = {3, 4, 5, 6, 7, 8}. Probability = 6/8 = 3/4 = 0.75.
(iv) Numbers less than 9 = {1, 2, 3, 4, 5, 6, 7, 8}. Probability = 8/8 = 1 (certain event).
(v) Multiples of 3 = {3, 6}. Probability = 2/8 = 1/4 = 0.25.
For more NCERT Solutions of Class 9 Ganita Manjari Chapter 7 The Mathematics of Maybe: Introduction to Probability Question Answer (2026-27)
https://www.tiwariacademy.com/ncert-solutions/class-9/maths/ganita-manjari-chapter-7/
See less