# How Fast is Anna's Pen Moving When It Hits the Ground?

What is the speed at which Anna's pen is moving when it hits the ground?

The pen is moving at a speed of 13.3 m/s when it hits the ground.

## Calculating the Speed of Anna's Pen

**Explanation:**To determine the speed at which the pen is moving when it hits the ground, we can use the equation for the final velocity, v, of an object in free fall: v^2 = u^2 + 2a s Where: - v is the final velocity - u is the initial velocity (which is 0) - a is the acceleration due to gravity (which is approximately 9.8 m/s^2) - s is the distance traveled (which is 9 m) Plugging in the values: v^2 = 0^2 + 2(9.8)(9) v^2 = 176.4 Taking the square root of both sides: v = 13.3 m/s So, the pen is moving at a speed of 13.3 m/s when it hits the ground.