Why is it harder to get something moving than to keep it moving?

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

An automobile steering wheel is shown. what is the ideal mechanical advantage? if the ama is 8, what is the efficiency of the steering wheel?

Consider a system to be two train cars traveling toward each other. what is the total momentum of the system before the train cars collide?   kg • what must the total momentum of the system be after the train cars collide?   kg •