In order for fusion to begin during the birth of a star, there needs to be a certain amount of A. mass. B. charge. C. density. D. volume.

Iridium is a component of cosmic dust that rains down upon the earth at a constant rate. Why did Luis Alvarez suggest measuring iridium levels in the K-T boundary? A. He hypothesized that the layer was caused by a supernova explosion. B.

Determine the resistance of a 250-w lightbulb connected to its proper source voltage of 110 v.

The Electrons in a beam are moving at 2.7x108 m/s in an electric field of 16000 N/C. What value must the magnetic field have if the electrons pass through the crossed fields undeflected?

Which part of the brain is responsible for homeostasis (regulating body temperature) ? A) cerebral cortex B) basal ganglia C) thalamus D) hypothalamus

If a seagull drops a shell from rest at a height of 10 m, how fast is the shell moving when it hits the rocks?

Why is there so much more carbon dioxide in the atmosphere of Venus than in that of Earth? Why so much more carbon dioxide than on Mars?

People have proposed driving motors with the earth's magnetic field. This is possible in principle, but the small field means that unrealistically large currents are needed to produce noticeable torques.

A hot air ballon with a mass of 500kg ascends at a constant rate of 1.5 m/s for 20s. how much work is done by the upward force?

A construction team gives an estimate of three months to repave a large stretch of a very busy road. The government responds that it's too much inconvenience to have this busy road obstructed for three months, so the job must be completed in one

Determine the time needed for the load at b to attain a speed of 10 m/s, starting from rest.