Materials that allow the charges of an electric current to move freely through them are called

a. insulators.

b. conductors.

c. resistors.

d. magnets.

It feels better to catch a hard ball while wearing a padded glove than to catch it bare handed. use the ideas of momentum and impulse to explain why?

Explain the difference between the synodic period of a planet and the sidereal period. why is the synodic period often much less than the sidereal period for the superior planets?

What happens to a magnetic field if the current carrying wire A has three times as many loops but the same current as the current carrying wire B? A. Wire A will have a lower magnetic field than wire B. B.

Explain how convections currents cause Earth's plates to move continuously

The frequency of a wave is 20 Hz. If the speed of the wave is 4 m/s, what is the wavelength?

Which of the following statements is true? A. Both chemical reaction rates and nuclear decay rates vary with the conditions of the reaction. B. Nuclear decay rates vary with the conditions of the reaction, but chemical reaction rates do not. C.

A star may form a black hole once it cannot?

Kai was 200 meters north of the library when he remembered he had to return some books to the library. It took him 200 seconds to do the round trip. Which best describes Kai's roundtrip?

The engine that powers a crane burns fuel at a temperature of 1500 oC. It is cooled by air at a temperature of 20 oC. The crane is used to lift a 1000 kg steel girder 30 m into the air.

The portion of a light ray that falls on a surface is a/an