You drop a penny down a well. Right before it hits the ground, the penny's velocity is 9 m/s. How long did the penny fall?

What is the magnitude of the resultant vector round your answer to the nearest tenth

Standing side by side ,you and a friend step off a bridge at different times and fall for 1.6s to the water below. your friend goes first, and you follow after he has dropped a distance of 2.0m. when your friend hits the water, is the seperation between the two of you 2.0m or more than 2.0m? verify your answer with a calculation.

What property of an object determines its inertia?