What is the reactive force when a fish swims through water? a. the force of the fish's tail on the water c. the force of gravity on the fish b. the force of air resistance on the fish d. the force of the water on the fish

Under the action of a constant force an object accelerates at 7.8 m/s2. what will the acceleration be if (a) the force is halved? (b) the object's mass is halved? (c) the force and the object's mass are both halved? (d) the force is halved and the object's mass is doubled?

Compare the horizontal displacement of the two balls as they travel to the ground. what do you observe?

The diagram shows a boulder rolling down a hill into a valley and then up the opposite hill. at which position does the boulder have the greatest kinetic energy? a b c d