A 0.0780 kg lemming runs off a 5.36 m high cliff at 4.84 m/s. What is it's kinetic energy (KE) when it lands?

5.01 J

Explanation:

At the top of the cliff, the lemming has potential energy and kinetic energy.

When it lands, all the energy is converted to kinetic energy.

Final energy = Initial energy

KE = PE₀ + KE₀

KE = mgh + ½ mv₀²

KE = (0.0780 kg) (9.8 m/s²) (5.36 m) + ½ (0.0780 kg) (4.84 m/s) ²

KE = 5.01 J