Question

A 2kg ball moves in a vertical circle of radius 50cm at a speed of 20m/s.Calculate the tension force in the rope attached to the ball at the top bottom and in the middle of the circle

Answer 1

m = 2 r = 50/100 u = 20

Velocity at top, V = √(u^2 - 2g(2r)

V = √(20^2 - 2(10)(2×50/100)

V = √(400 - 20)

V = √380

Tension at top, T = mV^2/r - mg

T = 2×380/(1/2) - 2×10

T = 1500N

Velocity at middle, V2 = √(u^2 - 2gr)

V2 = √(20^2 - 2(10)(1/2)

V2 = √(400 - 10)

V2 = √390

Tension at middle, T2 = mV2^2 - mg

T2 = 2×390/(1/2) - 2(10)

T2 = 1540N