What happens to a muscle when you exercise it?

In 2013, renewable energy provided 10% of the total energy used in the united states, and wind energy accounted for 17.4% of the renewable energy used. what percent of the total energy used in the united states in 2011was wind energy?

Z = y/x if z = 4.0 and y = 6.8 what is the value of x?

Which of the following is a simple machine?

Two oppositely charged parallel metal plates, 1.00 centimeter apart, exert a force with a magnitude of 3.60 * 10^-15 newton on an electron placed between the plates. Calculate the magnitude of the electric field strength between the plates.

Calculate the momentum for each ocean creature and then answer the question. A 500 kg dolphin swims at 4 m/s. A 700 kg sea turtle swims at 3 m/s. A 1,100 kg shark swims at 1.5 m/s. Which sea creature has the most momentum?

Plaskett's binary system consists of two stars that revolve in a circular orbit about a center of mass midway between them. This statement implies that the masses of the two stars are equal (see figure below).

Is mercury (the planet) rocky or gaseous (meaning relating to or having the characteristics of a gas.)

What does one prolonged blast emitted by boat a using an efficient sound producing device indicate?

Feng and Isaac are riding on a merry-ground. Feng rides on a horse at the outer rim of the circular platform, twice as far from the center of the circular platform as Isaac, who rides on an inner horse.

Alice did an experiment to find the relationship between the angle at which a ray of light strikes a mirror and the angle at which the mirror reflects the light. She placed a ray box in front of a mirror.