Question

What is work done by a body when changes its velocity frm 30km/h in 60 km/r?

Answer 1

Work done to increase the velocity of a car = Change in kinetic energy
m =  1500kg
u = 30km/h = 30*(5/18) m/s= 25/3 m/s
v = 60km/h = 60*(5/18) m/s = 50/3 m/s
Plug-in these values in above equations, we get
W = (0.5)(1500)(625/9)(4-1) = 156250 J = 156.25 KJ

Answer 2

Work done to increase the velocity of a car = Change in kinetic energy

=>W= m(v²-u²) /2-------(1)

m =  1500kg

u = 30km/h = 30x(5/18) m/s= 25/3 m/s

v = 60km/h = 60x(5/18) m/s = 50/3 m/s

Putting all this values in equation (1) we get

W = (0.5)(1500)(625/9)(4-1) = 156250 J = 156.25 KJ