Question

A 5.0kg ball is projected up along a plane that is inclined 20
degrees with the horizontal. What is its potential energy when it moved
2.3m up along the plane?

Answer 1

When the ball moved 2.3m up along the plane its vertical displacement will be:

$$h = 2.3\sin20\degree \space[m]$$

The potential energy is:

$$W = mgh$$

where $m = 5kg$ and $g = 9.81m/s^2$. Thus, obtain:

$$W = 5kg\cdot 9.81m/s^2\cdot 2.3\sin20\degree \approx 38.59J$$

Answer. 38.59 J.