No work is done because the object needs to be moved. The formula for work is Work = Force x Distance.
ANSWER:
3408.81 kg
STEP-BY-STEP EXPLANATION:
Given:
v = 111 m/s
Ek = 21000000 J
We have that the formula for kinetic energy is as follows:

We substitute the values given in the exercise and solve for m (mass)

The mass of the helicopter is 3408.81 kilograms.
angular vel to tangential vel
v=r omega
v = 56 x 100/60 x 2 pi
v = 56x5/3x6
v=560m/s as estimate
100 revs, 5.00m
I think it is d if not then im sorry