Question

A transport plane takes off from a level landing field with two gliders in tow, one behind the other. The mass of each glider is 700 kg, and the total resistance (air drag plus friction with the runway) on each may be assumed constant and equal to 1900 N. The tension in the towrope between the transport plane and the first glider is not to exceed 12000 N. Part A If a speed of 40 is required for takeoff, what minimum length of runway is needed? Express your answer using two significant figures. Part B What is the tension in the towrope between the two gliders while they are accelerating for the takeoff? Express your answer using two significant figures. Please try to explain how you get to the answer.

Answer 1

Answer:

(a)  Length =136.58 m

(b)  T=5995 N

Explanation:

for the glider in the back

T - 1900 = 700 a

for the glider in front

12000-T -1900 = 700a

add equations

12000-3800 = 1400 a

a=5.85 m/s^2

v^2 = v0^2 + 2 a x

40^2 = 2*5.85*x

Length =136.58 m

b) plug the a back into one of the previous formula

T -  1900 = 700*5.85

T=5995 N