How do we know that the universe is getting bigger faster and faster?

Why is there a leap year day every four years? A. to compensate for the 1/2 day that the earth revolves around the sun each year B. To compensate for the 1/4 day that the earth revolves around the sun every year. C. because Galileo said so

Why doesn't a transformer work with direct current? why is ac required?

8. How does the direction of friction compare to an object's direction of motion?

How much energy in joules would be produced if the sun converts 8 kg of mass totally into energy? (hints:) ?

A rifle with a longer barrel can fire bullets with a larger velocity than a rifle with a shorter barrel. a) Explain this using the impulse-momentum theorem. b) Explain this using the work-energy theorem

What will one see during an annular eclipse?

What is a inactive volcano?

Ways that charges can be transferred

If you drive at 100 km/hr for six hours how far will you go

Chemical bonds are formed from the attractive force of atoms for electrons. What is the force called?