Chapter 3: Work, Energy, Power & System of Particles (Set-1)

Work is said to be done when:

When force and displacement are perpendicular, work done is:

SI unit of work is:

Kinetic energy is:

The work–energy theorem states:

If net work on a body is zero, kinetic energy:

Work done by friction is always:

A force of 20 N moves a body 3 m in its direction. Work is:

Power is defined as:

Work done against gravity in lifting a mass m to height h is:

Gravity is a:

A non-conservative force:

Example of a non-conservative force is:

Work done by a conservative force in a closed path is:

Potential energy exists due to:

Air resistance is a:

Work done by friction in a closed loop is:

A conservative force has:

Centre of mass depends on:

Centre of mass of a uniform rod lies at:

COM of Earth–Moon system lies:

Motion of COM depends on:

In absence of external force, COM moves with:

For a system of particles, total momentum is related to:

COM may lie:

Momentum is:

SI unit of momentum is:

Momentum is conserved when:

Impulse equals:

Perfectly inelastic collision conserves:

In an elastic collision, kinetic energy:

Momentum is a:

Mechanical energy =

Mechanical energy is conserved when:

Potential energy of a spring is:

A rising ball loses kinetic energy because:

Energy cannot be created or destroyed refers to:

When velocity doubles, KE becomes:

A force does zero work when:

Work done by tension in uniform circular motion is:

A 2 kg object moving at 3 m/s has KE =

Work done by a variable force is found from:

If work = 100 J and time = 5 s, power =

If force acts opposite displacement, work is:

Unit of power is:

A 1 kg mass increases speed from 2 to 4 m/s. Work done is:

A body with momentum 10 kg·m/s and mass 2 kg has velocity:

Mechanical energy decreases when:

Work done by any internal force on a system is:

A conservative force always has: