An object moving at 39m/s takes 9s to come to a stop. what is the object’s acceleration?

Identical marbles are released from the same height on each of the following four frictionless ramps . compare the speed of the marbles at the end of each ramp. explain your reasoning

Efficiency is the ratio of to for a system a)power in to power in b)power in to power out c) power out to power out d) power out to power in

On mars a rock falls an unknown vertical distance from a resting position and lands in a crater. if it takes the rock 2.5 seconds to fall, how high is the cliff the rock fell from? mars' surface gravity is 3.8 m/s2. a. 9.5 m b. 11.9 m c. 15.2 m d. 23.8 m