A spherical ball of mass `20kg` is stationary at the top of a hill of height `100m` , it rolls down a smooth surface to the ground , then climbs up another bill of height of `30 m` and final rolls down to a horizontal base at a height of `20 m` about the ground . The velocity attained by the ball is

Explanation

To solve the problem of the spherical ball rolling down the hill and finding the velocity attained by the ball, we can use the principle of conservation of energy. Here’s the step-by-step solution:

### Step 1: Identify the initial and final heights
- The ball starts at a height of 100 m and ends at a height of 20 m after rolling down the hill and then rolling to the horizontal base.
- The change in height (h) is calculated as:
\[ h = \text{Initial Height} - \text{Final Height} = 100\, \text{m} - 20\, \text{m} = 80\, \text{m} \]
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