A 5000-kg freight car crashes into a 10,000-kg freight car at rest. They couple upon collision and move with a speed of 2 m/s. What was the initial speed of the 5000-kg freight car?

A force of 1 N accelerates a 1-kg mass at 1 m/s2.  The acceleration of a 2-kg mass acted upon by a force of 2 N is

We know that any body more dense than water will sink in water. Why?

A car by itself is capable of a certain maximum acceleration. When it tows a twice-as-massive car, its maximum acceleration is

The amount of friction that occurs when two blocks slide against each other depends on

Earth pulls on the Moon. Similarly the Moon pulls on Earth, evidence that

The Earlybird communication satellite hovers over the same point on Earth’s equator indefinitely because

When you push an object a certain distance while applying twice the force, you do

When the input piston of a hydraulic press is depressed 20 cm, the output piston is observed to move 1 cm. An input force of 1 N can raise no more than

Find the average speed of a rabbit that runs a distance of 28 m in a time of 2.6 s.