Question

If an object with a mass of `12 kg` changes speed from `9 m/s` to `10 m/s`, by how much does its kinetic energy change?

Answer 1

`"114 Joules"`

Explanation:

Kinetic energy is given as

`"KE" = 1/2\ "mv"^2`

Initial kinetic energy

`"KE"_i = 1/2\ "mv"^2 = 1/2 × "12 kg" × ("9 m/s")^2 = "486 J"`

Final kinetic energy

`"KE"_f = 1/2\ "mv"^2 = 1/2 × "12 kg" × ("10 m/s")^2 = "600 J"`

Change in kinetic energy

`Δ"KE" = "KE"_f - "KE"_i`

`Δ"KE = 600 J - 486 J" = color(indigo)("114 J"`

I hope that helps!