Chapter 3: Work, Energy, Power & System of Particles (Set-4)

Net work done on a body is equal to:

A force acts at an angle of 90°. Work done is:

If a body gains 30 J of KE, then work done is:

For work to be done, displacement must be:

If work done is negative, the body:

A force of 10 N causes 4 m displacement at 30°. Work =

KE of mass 1 kg moving at 6 m/s is:

Work = 40 J, displacement = 5 m. Force =

If force triples and displacement doubles, work becomes:

Work done by constant force is:

In a closed path, work done by gravity is:

Friction reduces:

Path-dependent work is done by:

Non-conservative force example:

Potential energy is defined for:

Spring force is:

Energy lost to friction appears as:

Work done by non-conservative forces equals:

COM of rigid body depends on:

For two masses, COM lies closer to:

COM of ring lies at:

Motion of COM changes only due to:

For an isolated system:

COM of projectile motion follows:

If two masses are equal, their COM lies:

COM of system is defined as:

Momentum is conserved when:

Momentum of 2 kg mass moving at 5 m/s:

Impulse is equal to:

In elastic collision:

Momentum is a:

Perfectly inelastic collision has:

Rate of change of momentum gives:

If impulse is 20 Ns on 4 kg mass, change in velocity =

Mechanical energy remains constant when:

A falling object converts:

PE is stored due to:

KE of a body with mass m and speed v is:

If KE increases, work done must be:

Falling body’s total ME remains constant when:

Compressed spring energy =

A 6 kg mass moving at 3 m/s has KE =

Work done by a force is zero when:

Momentum of system changes only when:

Area under F–x graph gives:

Power becomes maximum when:

If force is perpendicular to displacement, then:

In explosion, COM of fragments:

Total energy of an isolated system:

If KE = 50 J and PE = 150 J, total ME =