Question

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​

Answer 1

39.37 m/s²

Step-by-step 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