Question

Certain force acting on a 20 kg mass changes its velocity from 18 km/hr to 36km/hr Calculate the work done by force

Answer 1

m=20kg
u= 18 km/hr = 5m/s
v= 36 km/hr= 10m/s
K.E(1)= ½mu²=½ 20× 25= 250J
K.E(2)=½mv²=½ 20× 100= 1000J
Work done= K.E(2)-K.E(1) = 1000-250 = 750J