What is the mechanical energy of an airplane relative to the ground, if its mass is 100m
What is the mechanical energy of an airplane relative to the ground, if its mass is 100m and it climbed at a speed of 200 m / s to an altitude of 10 km?
m = 100 t = 100000 kg.
V = 200 m / s.
h = 10 km = 10000 m.
g = 10 m / s2.
E -?
The total mechanical energy of an airplane E is the sum of its kinetic Ek and potential energy En: E = Ek + En.
The kinetic energy of the plane Ek with mass m, which moves with a speed V, is determined by the formula: Ek = m * V ^ 2/2.
Ek = 100000 kg * (200 m / s) ^ 2/2 = 2 * 109 J.
We will express the potential energy of the aircraft Еп by the formula: Еп = m * g * h.
Ep = 100000 kg * 10 m / s2 * 10000 m = 10 * 10 ^ 9 J.
E = 2 * 10 ^ 9 J + 10 * 10 ^ 9 J = 12 * 10 ^ 9 J.
Answer: the total mechanical energy of the aircraft is E = 12 * 10 ^ 9 J.