Question

how much work to be done to increase the velocity of car from 18 kilometre per hour to 90 kilometre per hour in the mass of 2000 kg​

Answer 1

Answer:

Work done  to increase the velocity is 600 kJ

Explanation:

Change in kinetic  energy is the total work done

$v_{1}=18 km /hr =18 \times\frac{1000}{3600} =5 m/s\\\\v_{2}=18 km /hr =90 \times\frac{1000}{3600} =25 m/s$

change in kinetic energy is

$\Delta KE=\frac{1}{2} m(v_{2}^2-v_{1}^2)\\\\\Delta KE=\frac{1}{2} 2000(25^2-5^2)\\\\\Delta KE=600 kJ$

Work done  to increase the velocity is 600 kJ