Question

The maximum and minimum tensions in the string whirling in a circle of radius 2.5 m with constant velocity are in the ratio 5 : 3. Its velocity is

(A)  \(\sqrt{98}\)m/s

(B) 7 m/s

(C) \(\sqrt{490}\) m/s

(D) \(\sqrt{4.9}\) m/s

Answer 1

Answer is (A)  \(\sqrt{98}\)m/s

Even though particle is moving in a vertical loop, its speed remain constant. 

Tension at lowest point, T_max = \(\frac{mv^2}{r}\)+ mg

Tension at highest point, T_min = \(\frac{mv^2}{r}\)- mg