Work, Power, Energy

Question 1

Define work and also give it’s SI units

Answer 1

Work : Work is said to be done when a force acting on a body moves it through some distance in the direction of the force applied
It’s SI units are Joule

Question 2

Define Power and also give it’s SI units

Answer 2

Power: The rate of doing work is called power

It’s SI units are Watt

Question 3

Define Energy and also give it’s SI units

Answer 3

Energy: The capacity to do work is called energy

It’s SI units are Joule

Question 4

Which physical quantity remains constant in

1) an elastic collision
2) an inelastic collision

Answer 4

1) The total momentum and the KE of the system remains constant in elastic collision
2) The total momentum remains constant in inelastic collision

Question 5

State the conditions under which a force does no work

Answer 5

1. When the force is conservative
2. When the displacement is zero
3. When the displacement is perpendicular to the direction of force applied