# Work and Energy Worksheet-5

Work and Energy Worksheet-5

1. Write an expression for the kinetic energy of a body of mass m moving with a velocity v.

1. If the speed of a body is halved, what will be the change in its kinetic energy?

1. On what factors does the kinetic energy of a body depend?

1. Which would have a greater effect on the kinetic energy of an object : doubling the mass or doubling the velocity?

1. How fast should a man of 50 kg run so that his kinetic energy be 625 J?

1. State whether the following objects possess kinetic energy, potential energy, or both:

A man climbing a hill

1. State whether the following objects possess kinetic energy, potential energy, or both:

A flying aero plane

1. State whether the following objects possess kinetic energy, potential energy, or both:

A bird running on the ground

1. State whether the following objects possess kinetic energy, potential energy, or both:

A ceiling fan in the off position

1. State whether the following objects possess kinetic energy, potential energy, or both:

A stretched spring lying on the ground.

1. Two bodies A and B of equal masses are kept at heights of h and 2h respectively. What will be the ratio of their potential energies?

1. What is the kinetic energy of a body of mass 1 kg moving with a speed of 2 m/s?

1. Is potential energy a vector or a scalar quantity?

1. A load of 100 kg is pulled up by 5 m. Calculate the work done, (g = 9.8 m/s2)

1. State whether the following statement is true or false :

The potential energy of a body of mass 1 kg kept at a height of 1 m is 1 J.

1. What happens to the potential energy of a body when its height is doubled?

1. What kind of energy is possessed by the following?

A stone kept on roof-top.

1. What kind of energy is possessed by the following?

A running car.

1. What kind of energy is possessed by the following?

Water stored in the reservoir of a dam.

1. What kind of energy is possessed by the following?

A compressed spring.

1. Kinetic energy = (1/2)mv2

Where m = mass of the body And v = velocity of the body (speed of the body)

1. Becomes one-fourth

Kinetic energy = (1/2)mv2 If speed is halved KE will be one fourth.

1. Mass and speed

Kinetic energy = (1/2)mv2

1. Doubling the velocity

Since Kinetic energy = (1/2)mv2

1. 5 m/s

1. Both kinetic energy and potential energy

1. Both kinetic energy and potential energy

1. Only kinetic energy

1. Only potential energy

1. Only potential energy (rather elastic potential energy)

1. 1:2

Using PE = mgh

1. Using the formula

Kinetic energy = (1/2)mv2

2 J

1. Scalar

1. 4900 J

1. False

PE = mgh so value of g is to be put

1. Potential energy gets doubled

PE = mgh so if height is doubled PE is also doubled.

1. Potential energy

1. Kinetic energy

1. Potential energy

1. Potential energy