Question

If an object with a mass of `2 kg` changes speed from `14 m/s` to `15m/s`, by how much does its kinetic energy change?

Answer 1

Change in kinetic energy can be calculated using
`Delta E_k=1/2m(v_f^2-v_i^2)`

Explanation:

Kinetic energy is calculated using:

`E_k=1/2mv^2`
Change in `E_k` is just final minus initial, or
`Delta E_k=1/2mv_f^2-1/2mv_i^2`

which factors to

`Delta E_k=1/2m(v_f^2-v_i^2)`

So, in this case,

`Delta E_k=1/2 2kg(15^2-14^2)`

`Delta E_k=29J`