On a planet, a rock is dropped from the top of a 400-foot cliff. After 1 second, the rock is traveling feet per second. After seconds, the rock is traveling feet per second. a. Assume that the relationship between time, t, and speed, s, is linear and write an equation describing this relationship. Use ordered pairs of the form (time, speed).
b. Use this equation to determine the speed of the rock seconds after it was dropped.