Question

calculate the work required to be done stop a car of 1300 kg moving a velocity of 50 km/ h.

Answer 1

force applied =1300 kg
velocity=50km/hr=13.8m/s(approx)
kinetic energy = 1/2 mv^2
= 1/2 × 1300× (13.8)^2
=650× 190.44
=1 23 786 joules

here work done is in the form of kinetic energy
therefore work done =123786 joules.


hope it helps...