A 20.0-kg rock is dropped and hits the ground at a speed of 90.0 m/s. Calculate the rock's gravitational potential energy before it was dropped. (Ignore the effects of friction.)

What is the final stage of existence for each type of star?

During World War I, the Germans had a gun called Big Bertha that was used to shell Paris. The shell had an initial speed of 2.61 km/s at an initial inclination of 81.9° to the horizontal. The acceleration of gravity is 9.8 m/s^2.

According to a rule-of-thumb, each five seconds between a lightning flash and the following thunder gives the distance to the flash in miles.

If you want to lift a 5-kg box to a height of 2 meters, how much work must be done? O A. 2J O B. 50 J O C. 98 J O D. 100

A star's parallax angle is 1.0. How far away is the star in light years?

Why does momentum have a direction?

What is the difference between weight and mass?

An object has a mass of 8.00 kg. What is the gravitational force on the object by the earth?

Which of the following best characterizes the free energy change ΔG for an endothermic reaction under physiological conditions? A. The sign of ΔG is positive B. The sign of ΔG is zero C. The sign of ΔG is negative D.

In a recent hockey game, one player (m=100kg) was moving at a velocity of 8 m/s when he ran into another player (m=300kg) who was at rest (v=0m/s). After the collision, the two players were stuck together (moving with the same velocity).