The charge of an atom from an excited state to the ground state always requires

a. an increase in electron energy

b. release of visible light

c. absorption of energy

d. emission of electromagnetic radiation

Astrophysicists believe the dominant hot spots in the cosmic background radiation should be about 1° in angular size if the universe is flat. What do experimental measurements of this angular size tell us?

Glycerin, with a viscosity of 1.5 N ∙ s/m 2, is flowing with an average speed of 1.2 m/s through a tube that has a radius of 5.0 mm and is 25 cm long. What is the drop in pressure over the length of this pipe

Jake has noticed his best friend Alison cheating at chess several times this week. If she gets caught, she will be kicked off the chess team, of which she is the president. What should Jake do?

How does gravity affect the path of an arrow after it has been released from the bow?

In the diagrams, the solid green line represents Earth's rotational axis and the dashed red line represents the magnetic field axis. Which diagram accurately shows Earth's magnetic field?

What could be put into the center section of this Venn diagram?

Give two factors that will increase the magnetic field strength of an electromagnet

What is an example of total internal reflection at work?

Explaining how momentum can cause motion an astronaut on a space walk floats a little too far away from the space station. without air to push against, he cannot paddle back. however, the astronaut is holding a hammer.

A one-piece cylinder has a core section protruding from the larger drum and is free to rotate around its central axis. A rope wrapped around the drum of radius 1.39 m exerts a force of 3.34 N to the right on the cylinder.