Question

A body of mass 1 kg tied to one end of string is revolved in a horizontal circle of radius 0.1 m with a speed of 3 revolution/sec, assuming the effect of gravity is negligible, then linear velocity, acceleration and tension in the string will be :

• A. 1.88 m/s, 35.5 m/ $I=100\sin 200\pi t$ , 35.5 N
• B. 2.88 m/s, 45.5 m/ $\frac{1}{400}s$ , 45.5N
• C. 3.88 m/s, 55.5 m/ $\frac{1}{300}s$ , 55.5N
• D. none of these

Answer 1

Answer: (A)

Here: mass of the body = 1 kg Radius of circle = 0.1 m n = 3 rev/sec Hence, angular speed $\omega =2\pi \times 3=6\pi rad/\sec$ (1) linear speed $\upsilon =r\omega =0.1\times 6\times 3.14=1.88m/s$ (2) acceleration $a=r{\omega }^2=0.1\times {(6\pi )}^2=35.5m/s^2$ (3) tension in strip $T=mr{\omega }^2=1\times 0.1\times {(6\pi )}^2=35.5N$