Calculate the potential energy of a rock with a mass of 55kg while sitting on a cliff that is 27m high

How tall is a chair? Choose the best estimate. A. 1 mm B. 1 cm C. 1 m D. 10 m

Infer why the output force exerted by a rake must be less than input force?

A bicyclist was moving at a rate of 8 m/s, and then sped up to 10 m/s. If the cyclist has a mass of 120 kg, how much work was needed to increase his velocity? (Hint: Use the work-kinetic energy theorem.)

What information does the color of a star tell you?

A bicycle is going 7 m/s. He squeezes the brakes, giving him an acceleration of - 1.2 m/s2. How fast is the bicyclist going after 3 seconds of applying the brakes?

A baseball player is dashing toward home plate with a speed of 3.8 m/s when she decides to hit the dirt. She slides for 1.3 s, just reaching the plate as she stops (safe, of course).

The water that powers the generators enters and leaves the system at a low speed (thus we can neglect its change of kinetic energy) and loses 160 m of altitude during the process.

What is: the fastest car the fastest animal the fastest human the fastest aeroplane

Why is gravitational potential energy negative?

Imagine an elevator crowded with too many passengers for such a small space. This situation would be a good analogy for a substance with what property