Find the total energy (ft-lb) of an aircraft weighing 20,000 lbs at 5,000 ft true altitude and 200 KTS true air speed. Group of answer choices

Hello the options to your question is missing below are the options

2 x 10^8 ft-lb

15527950 ft-lb

2.8 x 10^7 ft-lb

13.55 x 10^7 ft-lb

Answer : 13.55 * 10^7 ft-Ib

Explanation:

Given data :

weight of Aircraft (p) = 20000 Ibs

height ( h ) = 5000 ft

Velocity = 200 KTS  = 370 km/h ( 10277 m/s) where 1 KTS = 1185 km/h

calculate the total energy

Total energy = potential energy + kinetic energy

potential energy = mgh = p * h =20000 * 5000 = 100 * 10^6 ft-Ibs

kinetic energy = 1/2 mv^2 = 1/2 * 625 * (33709)^2 = 3551 *10^6 ft-Ibs

where ; m = p/g = 20000 / 32 = 625 Ibs

             v = 10277 m/s ≈ 33709 ft/s

hence total energy = 100 * 10^6 + 3551 * 10^6 = 1355*10^7 ft-Ibs

kepler used the data from tycho blahe (his mentor) to construct the laws of planetary motion.