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Mayank1444
@mayank1444
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Joined: Oct 11, 2021
Last seen: Nov 14, 2021
Topics: 0 / Replies: 2157
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Answer to: What do you understand by the kinetic energy of a body? (b) A body is thrown vertically upwards. Its velocity goes on decreasing. What happens to its kinetic energy as its velocity becomes zero?

(a) Kinetic energy of a body is the energy due to motion. (b) The kinetic energy of the body will be equal to zero as kinetic energy is directly pro...

4 years ago
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Answer to: Define the term ‘energy’ of a body. What is the SI unit of energy. (b) What are the various forms of energy? (c) Two bodies having equal masses are moving with uniform speeds of v and 2v respectively.

(a) Energy is defined as the ability to do work and joule is the SI unit of energy. (b) Following are the various forms of energy: Kinetic energy...

4 years ago
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4 years ago
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Answer to: A weightlifter is lifting weights of mass 200kg up to a height of 2 meters. If g = 9.8 m/s^2, calculate: (a) potential energy acquired by the weight (b) work done by the weightlifter

Mass, m = 200 kg Height, h = 2m Acceleration due to gravity, g = 9.8 m/s2 (a) Potential energy = mgh = 3920 J (b) Work done against gravity...

4 years ago
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Answer to: A boy weighing 40 kg makes a high jump of 1.5m (a) What is his kinetic energy at the highest point? (b) What is his potential energy at the highest point?

Mass of boy, m = 40 kg Height, h = 1.5 m Acceleration due to gravity, g = 10 m/s2 (a) At highest point velocity, v = 0 Therefore, KE = 0 ...

4 years ago
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4 years ago
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Answer to: How much is the mass of a man if he has to do 2500 joules of work in climbing a tree 5m tall?

Mass of man = m Height of tree, h = 5m Work done, W = 2500J Acceleration due to gravity, g = 10 m/s2 W = mgh m = m = 50 kg

4 years ago
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Answer to: Give two examples where a body possesses both kinetic energy as well as potential energy.

Following are the two examples where a body possess both kinetic energy as well as potential energy: (a) a flying airplane (b) A man climbing st...

4 years ago
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Answer to: On what factors does the gravitational potential energy of a body depend? (b) Give one example each of a body possesses both, (i) kinetic energy (ii) potential energy

(a) Following are the factors on which the gravitational potential energy of a body depend on: (i) mass of the body (ii) height at which the body...

4 years ago
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Answer to: Explain by an example that a body may possess energy even when it is not in motion.

Storing of water in the reservoir is an example of a body which possess energy even when it is not in motion. The energy stored by this water is known...

4 years ago
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Answer to: A car is being driven by a force of 2.5 x 10^10 N. Travelling at a constant speed of 5 m/s, it takes 2 minutes to reach a certain place. Calculate the work done.

Force, F = 2.5 × 1010 N Velocity, v = 5 m/s Time, t = 2 minutes = 120 s Distance, s = vt = 600m Work done, W = Fs = 15 × 1012 J

4 years ago
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Answer to: A body of mass 2kg is thrown vertically upwards with an initial velocity of 20 m/s. What will be its potential energy at the end of 2s?

Mass of the body, m = 2 kg Initial velocity, u = 20 m/s Acceleration due to gravity, g = 10 m/s2 Height reached = h Time, t = 2 s Using ...

4 years ago
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Answer to: To what height should a box of mass 150 kg be lifted, so that its potential energy may become 7350 joules?

Mas of the box, m = 150 kg PE = 7350 J Acceleration due to gravity, g = 9.8 m/s2 PE = mgh h = h = 5m

4 years ago
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Answer to: When is the work done by a force on a body: (a) positive (b) negative (c) zero

Work done by a force applied on a body is: (a) When the direction of motion of the body and the force acting in the same direction, work done is po...

4 years ago
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