A helicopter of mass 2000 kg rises with a vertical acceleration of `15ms^-2`. The total mass of the crew and passengers is 500 kg. Give the magnitude and direction of the (g`=10ms^-2`)
(a) Force on the floor of the helicopter by the crew and passengers.
(b) action of the rotor of the helicopter on the surrounding air.
(c ) force on the helicopter dur to the surrounding air.

Explanation

Given, mass of helicopter `(m_(1)) = 2000 kg`
Mass of the crew and passengers `m_(2) = 500 kg`
Acceleration in vertical direction `a = 15 m//s^(2) (uarr)` and `g = 10 m//s^(2) (darr)`
(A) Force on the floor of the helicopter by the crew and passengers
`m_(2) ( g + a) = 500 (10 + 15 )N` `500 xx 25 N = 12500`
(B) Action of the rotor of the helicopter on the surrounding air = `(m_(2) + m_(2)) (g + a)`
`= (2000 + 500) xx (10 + 15) = 2500 xx 25` = 62500 N (downwards)
(C) Force on the helicopter due to the surrounding air
= reaction of force applied by helicopter. = 62500 N (upward)
Note: We should be very clear when we are balancing action and reaction forces. We must know that which part is action and which part is reaction due to the action.