Question

The truck's mass is 5000 kilograms, which speeds up to 25 meters per second from 35 meters per second, then determine the change in its kinetic energy.

Answer 1

kinetic energy formula:- 1/2mv^2

m= 5000

difference in v:- 35-25= 10m/s

1/2(5000)(10)(10)

250000 Joules

2.5x10^5 Joules

Answer 2

Mass, m = 5000 kg

Initial KE = mu^2/2 = 5000*25^2/2

Final KE = mv^2/2 = 5000*35^2/2

So, Change in KE = 5000(35^2 - 25^2)/2

                             = 1500000 J = 1500 kJ