Question

what is work done to increase velocity of car from 36 km/hr to 72 km/hr if mass of car is 1500 kg?

Answer 1

Formula :

Work done = increase in kinetic energy

                   = 1/2 m v² - 1/2 m u²

                   = 1/2 m ( v² - u² )

Given :

mass = 1500 kg

v = 72 km/hr

u = 36 km/hr

Work = 1/2 m ( v² - u² )

         = 1/2 × 1500 × ( 72² - 36² )

         = 750 × ( 72 + 36 )( 72 - 36 )

         = 750 × 108 × 36

         = 750 × 3888

         = 2916000

         = 2.916 × 10⁶

ANSWER:

The work done is 2.916 × 10⁶