Question

The speed of a vehicle of mass 500 kg increases from 36km/hr to 72 km/hr .calculate the increase in its kinetic energy

Answer 1

Answer:

75000 J or 75 kJ

Explanation:

Given:-

u= 36 km/h=10 m/s

v=72 km/h = 20 m/s

m= 500 kg

K.E.= ?

Formula:-

Change in K.E.= 1/2*m*(v^2-u^2)

Solution:-

Change in K.E.= 1/2*500*(20^2-10^2)

                        = 250(400-100)

                        = 250*300

                        = 75000 J or 75 kJ