Question

If an object with a mass of `2 kg` changes speed from `2 m/s` to `5m/s`, by how much does its kinetic energy change?

Answer 1

`11J`

Explanation:

Kinetic energy is calculate dby the formula`" "KE=1/2mv^2`

so in this case

`m=2 kg,v_1=2 ms^(-1),v_2=5ms^(-1)`

`KE_(1)=1/2xx2xx2^2=4 J`

`KE_2=1/2xx2xx5^2=25 J`

`Delta KE=KE_2-KE_1=25-4=11 J`