Question

A worker drives a spike into a rail tie with a 2.00-kg sledgehammer. This caused the internal energy of the hammer and spike to increase by 1,250 Joules. If one half of the hammer’s kinetic energy is converted into the internal energy of the hammer and spike, what was the hammer’s speed when it hit the spike? In your computations, for the mass, use the mass of the hammer only.

Answer 1

50 m/s

Step-by-step explanation:

half of the hammer’s kinetic energy = internal energy of the hammer and spike

½ (½ mv²) = U

v² = 4U/m

v² = 4 (1250 J) / (2.00 kg)

v = 50 m/s