A horizontal 803-N merry-go-round is a solid disk of radius 1.41 m and is started from rest by a constant horizontal force of 49.7 N applied tangentially to the edge of the disk. Find the kinetic energy of the disk after 2.90 s.

The kinetic energy of the disk is 254.4 J.

Explanation:

The kinetic energy of the disk is given by:

The moment of inertia of the solid disk is:

The mass is:

Now, we need to find the angular acceleration as follows:

Also, the torque is related to the tangential force:

Now, we can find the angular speed:

since it is started from rest  

Finally, the kinetic energy of the disk is:

Therefore, the kinetic energy of the disk is 254.4 J.

I hope it helps you!