The ceiling of an arena is 79 m above the floor. What is the minimum speed that a thrown ball would need to just reach the ceiling?

m/s

39.37 m/s²

Explanation:

We are given;

Height from the floor to the ceiling as 79 m

We need to determine the minimum speed for the ball to reach the ceiling.

We will need to know;

The potential energy of the ball at the ceiling will be maximum while the kinetic energy will be minimum. This means, that the kinetic energy that was possessed by the ball while in motion was converted to potential energy.

Therefore, potential energy = kinetic energy

That is;

mgh = 0.5 mv²

simplifying it, we get;

gh = 0.5 v², taking g as 9.81 m/s²

Then;

v² = 79 m * 9.81 m²/s * 2

v² = 1549.98

v = √1549.98

=39.37 m/s

Therefore, the minimum speed the ball needs to reach the ceiling is 39.37 m/s²