Question

A piston motion moves a 25 kg hammerhead vertically down 1 m from rest to a velocity of 50 m/s in a stamping machine. What is the change in total energy of the hammerhead? 

Answer 1

C.V. Hammerhead 

The hammerhead does not change internal energy (i.e. same P, T), but it does have a change in kinetic and potential energy.

E₂ – E₁ = m(u₂ – u₁) + m[(1/2)V₂ ² – 0] + mg (h₂ - 0) = 

0 + 25 × (1/2) × 50² + 25 × 9.80665 × (-1)

= 31250 – 245.17 = 31005 J = 31 kJ