Which power source uses the earth's internal heat

Why do different elements emit different colors of light

One cubic foot of water can store 312 Btu of thermal energy. On a cold winter day a well-constructed home may require 100,000 Btu of nighttime space heating. What is the volume of water required to store this energy?

How are weight and mass alike

Which of the following statements concerning the electric field inside a conductor is true? A) The electric field inside a conductor is never zero. B) The electric field inside a conductor is always zero.

Which of the following factors is responsible for decreased compliance and obedience in groups? A. when an authority figure is highly respected by institution B. the presence of at least one conflicting opinion in the group C.

A ball is being rolled by a normal push of 1000N. it is opposed by friction which has a force of 0.3kN and air resistance which has a force of 23N. Calculate the resultant force.

Consider a Young's two-slit experiment in which the wavelength of light is 37% smaller than the distance between the slits.

Which of the following situations would produce an average velocity of zero? A) a round-trip to school and back B) a horse galloping in a field C) the criss-crossing path of a flying bug D) a trip, first to the moon, then onto Mars

A 111.6 g sample of iron was heated from 0°C to 20°C. It absorbed 1004 J of energy. What is the specific heat capacity of iron?

A car is driving towards a brick wall at a constant velocity (don't try this at home!) and the driver honks the horn of the car. the sound of the horn reflects from the wall and the echo is heard by the driver.