Question

A rock is thrown vertically upward and reaches a maximum height of 25 meters above the surface of the Earth. What is the rock's speed at its maximum height?

1) 9.8 m/s
2) 0.0 m/s
3) 24 m/s
4) 3.1 m/s

Answer 1

The speed of the rock at its maximum height is 0.0 m/s because at this point it has momentarily stopped moving upward and is about to start falling.

Step-by-step explanation:

The speed of the rock at its maximum height is 0.0 m/s. When an object is thrown vertically into the air, it will move upwards until gravity slows it down to a stop before it starts to fall back down. At the maximum height, the vertical velocity of the object is zero because it has stopped moving upward and is about to start its descent. This is a concept explained by the physics of projectile motion where gravity is the only force acting on the object (assuming air resistance is negligible), causing it to slow down as it moves against the force of gravity.