Mass of helicopter , m1=1000kg
Mass of the crew & passengers , m2=300kg
Upward acceleration of the helicopter , a = 15m/s2
Total mass of the system, m = 1000+300 = 1300 kg
(a) Reaction force on the floor of helicopter by the crew and passengers is given by:
R = m2(g+a) = 300(10+15) = 7500 N
Reaction force is directed upward, thus the helicopter is accelerating vertically upwards but according to Newton’s 3rd law, the force on the floor of helicopter by crew and passenger will be acting downward and hence equal to the upward force, i.e 7500 N.
(b) Action of rotor of helicopter on surrounding air will be vertically downwards because of mass of helicopter and passenger.
(c) Force on the helicopter due to surrounding air is the reaction of the force applied by the rotor on the air (By Newton’s 3rd law),
F = 32500 N