question_answer 26)

A helicopter of mass 1000 kg rises with a vertical acceleration of . The crew and the passengers weigh 300 kg. Give the magnitude and direction of (i) force on the floor by the crew and passengers. (ii) action of the rotor of the helicopter on the surrounding air. (iii) force on the helicopter due to the surrounding air. Take                                   [Delhi 03]  

Answer:

Mass of helicopter, M = 1000 kg Mass of the crew and passengers, m = 300 kg Vertically upward acceleration, (i) Force on the floor by the crew and passengers, F = Apparent weight = m (g + a)  vertically downwards. (ii) Action of the rotor of the helicopter on the surrounding air                                         = Apparent weight of the helicopter, crew    and passengers                                             = 32500 N, vertically downwards.              (iii) Force on the helicopter due to the surrounding air is equal and opposite to the action of the rotor of the helicopter on the surrounding air.  Force on surrounding air = 32500 N, vertically upwards.