Question

A car is moving with a velocity of 54km/h. The kinetic energy of a boy of mass 40kg sitting in the car is

Answer 1

The formula for kinetic energy is KE=(1/2)mv^2

.5*40*54^2 = 58320

Answer 2

Answer: KE = 4500 J

Explanation: Solution:

First convert 54 km/h to m/s

54 km/h x 1000m/ 1km x 1h /3600s

= 15 m/s

Use the equation for Kinetic Energy and substitute the values:

KE = 1/2 mv²

= 1/2 40 kg x ( 15 m/s)²

= 1/2 9000

= 4500 J