Question -
Answer -
(a) Mass of the helicopter, mh =1000 kg
Mass of the crew and passengers, mp =300 kg
Total mass of the system, m =1300 kg
Acceleration of the helicopter, a =15 m/s2
Using Newton’s second law of motion, thereaction force R, on the system by the floor can be calculated as:
R – mpg =ma
= mp(g + a)
=300 (10 + 15) = 300 × 25
=7500 N
Sincethe helicopter is accelerating vertically upward, the reaction force will alsobe directed upward. Therefore, as per Newton’s third law of motion, the forceon the floor by the crew and passengers is 7500 N, directed downward.
(b) Using Newton’s second law of motion, thereaction force R’, experienced by the helicopter can be calculatedas:
= m(g + a)
=1300 (10 + 15) = 1300 × 25
=32500 N
Thereaction force experienced by the helicopter from the surrounding air is actingupward. Hence, as per Newton’s third law of motion, the action of the rotor onthe surrounding air will be 32500 N, directed downward.
(c) The force on thehelicopter due to the surrounding air is 32500 N, directed upward.