Scientists can measure the amounts of different elements found in the universe. Which element's concentration in the universe is evidence for the big bang theory?

A. Helium

B. Uranium

C. Calcium

D. Iron

How does a generator work?

Who does the little boy in the animation with the compass grow up to be?

An object is dropped from rest from a height of 4.4 107 m above the surface of the Earth. If there is no air resistance, what is its speed when it strikes the Earth?

A light wave moves from a medium where particles of matter are closely packed to a medium made of very little matter. How do you expect the light wave to travel differently? The light will change wavelength and lose energy.

How do geologists use seismic waves to learn about the Earth's interior?

Bus A and Bus B leave school on a field trip when a stopwatch reads zero. Bus A travels at a constant 50 km/h, and Bus B travels at a constant 75 km/h. How far are the two buses from school when the stopwatch reads 1.5 h?. a ... Bus A is 76.

When observed from Earth, the wavelengths of light emitted by a star are shifted toward the red end of the electromagnetic spectrum. Why does this redshift occur?

Object A has a length of 3 cm, a width of 10 cm, and a height of 2 cm. Object B is dropped into a graduated cylinder. It displaces 60 mL of water. The volume of object A is:

Is the following sentence true or false? Some information about an object or process may be missing from a model.

If V is a velocity, l a length, and v a fluid property having dimensions of L2T-1, which of the following combinations are qualitatively dimensionless (show work for a through d) : (a) V l v (b) Vl/v (c) V2v (d) V / (l v)