Question

At a playground is a children spin-around ride. It is effectively a metal disk 10 cm thick with a 3 m diameter and a hand rail. It is spinning at 2 revolution in 10 sec.

1.determine angular displacement

2. Av.angular velocity

3.tang.velocity of the child sitting on the edge of the ride.

4.rotational KE

5.if the child lets go of the hand rail, calculate the linear KE of the child.

Answer 1

Since the DIsk is spinning at 2 revolution in 10 sec so

1) Angular displacement =

angular displacement is = 4 * 180 = 720 degree

2) Av Angular velocity

angular velocity = 1.2566 rad/s

3) Tangential velocity of the child sitting at edge

    

     tangential velocity of cheild is 1.8850 m/s

4) Rotational Kinetic energy is given by

   

5) Linear kinetic energy of the child is given by