NTA Abhyas JEE Main2020PhysicsLaws of MotionPractice
An aircraft loops a vertical loop of radius R = 500 m with a constant velocity v = 360 kmh - 1 . Find the weight of the flier of mass m = 70 kg in the lower, upper, and middle points of the loop.
Options
- A2 . 1   kN ,   0 . 7   kN ,   1 . 5   kN
- B0 . 7   kN ,   1 . 5   kN ,   2 . 1   kN
- C1 . 5   kN ,   2 . 1   kN ,   0 . 7   kN
- Dnone of these
Correct answer
A. 2 . 1   kN ,   0 . 7   kN ,   1 . 5   kN
Step-by-step solution
Forces on the flier in the frame of aircaraft (non inertial reference frame) is: (i) Normal reaction (N) (ii)Pseudo force m v 2 R (iii) Gravitational force d(mg) According to problem, v T = v b = v m = v The net force on flier at every point should be zero in the frame of aircraft. For top point T, N T + mg = mv T 2 R ∴ N T = mv 2 R - mg = 0.7 kN For bottom point, N B = mg + mv b 2 R = mg + mv 2 R = 2.1 kN. For middle point, N m = mv 2 R 2 + mg 2 = 1 . 5 k N