What do we need to measure in order to determine a star's luminosity?

What kind of energy is used when there is friction between two items?

A crate is placed on a slipway with gradient 1 in 5 (20%). The slipway has a coating of dry seaweed, coefficient of friction m 1⁄4 0.6. Show that the crate is stable.

A miner finds a small mineral fragment with a volume of 5.74 cm^3 and a mass of 28.7 g. What is the density of that mineral fragment?

Which of the following statements about the planets is not true? a. Mercury has a greater eccentricity than Venus. b. Uranus has the smallest mass of the outer planets. c. Neptune has the shortest rotation period of any planet. d.

Vicente is going to spend the afternoon in his yard. He has the choice to get in the pool, lay on a cotton chaise longue, sit on the porcelain tile bordering the pool, or sit on a plastic chair. The specific heats of these items are: Water = 4.

Determine the total mechanical energy of a 250 g baseball if it has a velocity of 30 m/s when it leaves the pitcher's hand 1.2m above the ground.

When distances were carefully measured from Earth to globular clusters above and below the Milky Way plane (where our view of them is not obscured by interstellar dust and gas), their distribution was found to be

Imagine you transfer heat into a gas. This heat splits up in two different ways: Additional thermal energy making the gas hotter and "fuel" for the gas to do work. Let's suppose, 64% of the transferred heat transforms into thermal energy.

How much heat is absorbed by a 61g iron skillet when its temperature rises from 5oC to 29oC?

Explain the relationship between motion and frame of reference.