What is the work to be done to increase the velocity of a car from `30kmh^(-1)` to `60kmh^(-1)`, if the mass of the car is `1500kg`?

Explanation

Mass of the car `m=1500kg`,
Initial velocity of car `u=30kmh^(-1)`
`=(30xx1000m)/(60xx60s)`
`=(25)/(3)ms^(-1)`
Similarly, the final velocity of the car,
`v=60kmh^(-1)`
`=(50)/(3)ms^(-1)`
Therefore, the initial kinetic energy of the car,
`E_(kl)=(1)/(2)m u^(2)`
`=(1)/(2)xx1500kgxx((25)/(3)ms^(-1))^(2)`
`=(156250)/(3)J`
The final kinetic energy of the car,
`E_(kf)=(1)/(2)xx1500kgxx((50)/(3)ms^(-1))^(2)` `=(625000)/(3)J`
Thus, the work done = Change in kinetic energy
`=E_(kf)-E_(kl)`
`=156250J`