Question

Airplane takeoff from an aircraft carrier is assisted by a steam driven piston/cylin-der with an average pressure of 200 psia. A 38 500 lbm airplane should be accelerated from zero to a speed of 100 ft/s with 30% of the energy coming from the steam piston. Find the needed piston displacement volume. 

Answer 1

C.V. Airplane. No change in internal or potential energy; only kinetic energy is changed.

E₂ – E₁ = m (1/2) (V₂² - 0)

= 38 500 lbm × (1/2) × 1002 (ft/s)2 

 = 192 500 000 lbm-(ft/s)2

= 5 983 092 lbf-ft 

The work supplied by the piston is 30% of the energy increase.