Question

Barney is flying a 1200kg helicopter. If he is accelerating towards the ground at 3.15m/s^2, what is the force applied to the rotors by the air?

Answer 1

As per the given question,

Mass of the helicopter =1200 kg

downward acceleration $(a)=3.15 m/sec^2$

gravitational acceleration $=9.8 m/sec^2$

Let the upward force is F.

So, $mg-F= ma$

$\Rightarrow F=mg-ma$

$\Rightarrow F=1200(9.8-3.15)=6.65\times 1200N$

$\Rightarrow F=7980N$