Question

A 4100 kg helicopter accelerates upward at 2.44 m/s^2. The acceleration of gravity is 9.8 m/s^2. What lift force is exerted by the air on the propellars? Answer in N.

I wasn't sure which way to approach this problem, so i tried it two different ways:

A. 2.44(4100)= 10,004 N
or
B. 2.44(9.8)=23.912
4100(23.912)=98,072 N

Answer 1

a + g = 2.44m/s^2,
a + (-9.8) = 2.44,
a = 2.44 + 9.8 = 12.24m/s^2.

F = ma = 4100 * 12.24 = 50,184N.

Answer 2

thankyou so much!