Question

A vehicle of mass 1,500 kg is traveling at a speed of 50 km/hr. What is the kinetic energy stored in its mass? Calculate the energy that can be recovered by slowing the vehicle to a speed of 10 km/hr.

Answer 1

Step-by-step explanation:

Given

mass of vehicle
`m=1500\ kg`

Speed of vehicle
`u=50\ km/hr\approx 13.89\ m/s`

Kinetic Energy Possessed by mass

`K_i=(1)/(2)mu^2`

`K_i=(1)/(2)* 1500* (13.89)^2`

`K_i=144.69\ kJ`

when vehicle is slowed down to speed of
`v=10\ km/hr\approx 2.78\ m/s`

Kinetic Energy at this speed

`K_f=(1)/(2)mv^2`

`K_f=(1)/(2)* 1500* (2.78)^2`

`K_f=5.78\ kJ`

Energy Recovered
`=K_i-K_f`

Energy Recovered
`=144.69-5.78=138.9\ kJ`