1.
When a coolie walks on a horizontal platform with a load on his head, the work done by the coolie on the load is zero.
2.
When a body falls freely under gravity, then the work done by the gravity is ________
3.
When a gas filled in a cylinder fitted with a movable piston is allowed to expand, the work done by the gas is positive.
5.
If an object has kinetic energy, then it also must have ____
6.
Which of the following is not a unit for power?
7.
An object with mass "m" kilograms is suspended "h" meters above the ground by a string. If the string is cut, what will the velocity of the object be at the instant it hits the ground?
8.
A moving hammer drives a nail into the wood. It has kinetic energy.
9.
A block with a mass of m crosses a rough horizontal surface at a constant speed of v. The coefficient of kinetic friction between the block and the surface is
µ. How much power must be produced in order to overcome the friction force?
10.
A gardener pushes a lawn roller through a distance of 20m. If he applies a force of 20kg weight in a direction inclined at 60° to the ground, find the work done by him. (g=9.8m/s2)
13.
The type of energy possessed by a simple pendulum, when it is at the mean position is:
14.
Mud thrown on a wall and sticking to it is an example for _____
15.
When a body is lifted, the work done by the gravitational force is positive.
18.
A bullet fired from a gun can pierce a target due to its ___________
19.
A man of mass 50 kg jumps to a height of 1 m. His potential energy at the highest point is (g = 10 m/s2):
20.
When a massive body collides against a light body at rest ____
21.
If a force acts perpendicular to the direction of motion of a body, what is the amount of work done?
22.
A machine does 2500 J of work in 1 min. What is the power developed by the machine?
24.
When a light body collides with a massive body at rest _____
25.
For a body moving in a circular path, the work done by the centripetal force is ________
