Circular Motion

Question

Kangaroo Jack is trying to catch a crane with a bola. The mass on the end of the bola is 250g and the bola makes 3 revolutions every 2 seconds with a velocity of 11 m/s. How long is the bola?

Answer 1

Hope this is still useful for you....

In a circular motion confined to a radius r, the linear and angular velocities are related by

v = ω*r --------- 1

Angular speed is the No. of radians traversed in one second. If t is time taken to cover 1 full rotation 2π, then angular speed is given by

ω = 2π/t --------- 2

You are given that the bola makes 3 full rotations in 2s. So the bola covers 3*2π radians in 2secs. Using the previous equation, you can calculate

ω = 3π radians/sec

Use equation 1 to calculate the radius (which is also the length of the bola)

r = 11/3π m

= 1.167 m