Question

what is work energy theorem,prove it for a constant force?

Answer 1

The Work-energy theorem explains the reasons behind this Physics of no work! Work is said to be done when an acting force displaces a particle. So, there must be a relation between Work and kinetic energy. This relation between the kinetic energy of an object and workdone is called “Work-Energy Theorem”.

Answer 2

let a body change its speed from v to u due to application of constant force F within a distance s
a=v2 - u2/ 2s

W= F.s = mas

= m ( v2-u2).s / 2s = 1/2 mv2 - u2= Kf- Ki

W= Kf- Ki

This is work energy theorem.