Question

20j of work is done in accelerating a 4kg mass from rest across a horizontal frictionless surface the K.E gained by the mass.

Answer 1

Work energy Theorem

• according to work energy Theorem , the net work done on any object is equals to its change in Kinetic Energy.

$\implies\bf W_{all} = \Delta{KE}$

So during the process when get accelerated from rest it gained 20 J of work in the form of energy.

• initial Kinetic energy = 0

$\implies\rm W_{all} = KE_f - KE_i$

$\implies \rm 20J = KE_f$

★Gained in Kinetic energy is also 20J