Question

If an object with a mass of `15 kg` changes speed from `25m/s` to `14 m/s`, by how much does its kinetic energy change?

Answer 1

`Delta E_k=-3217,5J`

Explanation:

`Delta E_k=1/2*m(v_f^2-v_i^2)`
`Delta E_k=1/2*15(14^2-25^2)`
`Delta E_k=1/2*15(196-625)`
`Delta E_k=-1/2*15*429`
`Delta E_k=-3217,5J`