Why do black holes happen?

How do the nonliving parts of earth's systems provide the basic materials to support life?

The moon clearly exhibits a light and dark portion during most of the month except during full moon. What causes the dark portion of any phase to change in size, that is, become either more or less black?

A bowling ball travels at 2.0 m/s. It has 16 J of kinetic energy. what Is the mass of the bowling ball in kilograms?

What distance was an object moved by a force of 40 N if the work was 600 joules

Which ocean is spreading (getting larger) due to plate tectonic movement

To determine waves frequency you must know the what

What is the average speed in miles per hour of the car that traveled a total of 200 miles in 5.5 hours

A solid weighs 277.5 g in air and 212.5 g when totally immersed in the liquid of density 0.9 g / cc. Calculate the density of the solid.

Who first described the double-helix structure of DNA?

Suppose you are holding a basketball while standing still on a skateboard you are and the skateboard have a mass of 50 kg you throw the basketball with a force of 10 N what is your acceleration before and after you throw the ball