Question

If an object with a mass of `2 kg` changes speed from `3 m/s` to `5 m/s`, by how much does its kinetic energy change?

Answer 1

I found `DeltaK=16J` from this we deduce that energy was added to the system allowing it to accelerate and so change the velocity.

Explanation:

Kinetic Energy `K` is given as:
`K=1/2mv^2`
The change in kinetic energy will be:
`DeltaK=1/2mv_f^2-1/2mv_i^2=1/2m(v_f^2-v_i^2)`
With our data:
`DeltaK=(1/cancel(2))cancel(2)(5^2-3^2)=25-9=16J`