A juggler juggles three balls in a continuous cycle. Any one ball is in contact with his hand for one-fifth of the time. Describe the motion of the centre of mass of the three balls. What average force does the juggler exert on one ball while he is touching it?

Explanation

To solve the problem, we will break it down into two parts: describing the motion of the center of mass of the three balls and calculating the average force exerted by the juggler on one ball while he is touching it.

### Step 1: Describe the Motion of the Center of Mass

1. **Understanding the Juggling Cycle**:
- The juggler has three balls, and any one ball is in contact with his hand for one-fifth of the time. This means that during the juggling cycle, the juggler is continuously tossing and catching the balls.
- Since there are three balls, while one ball is in contact with the juggler's hand, the other two balls are in the air.

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