Where on a roller coaster are there equal amounts of potential energy and kinetic energy?

What is the average speed of a car that travels 40 mph for 1 hour and 60 mph in another hour?

You are given a vector a = 125i and an unknown vector b that is perpendicular to a. the cross-product of these two vectors is a × b = 98k. what is the y-component of vector b?

Which changes would result in a decrease in the gravitational force btween two objects? check all that apply