The rate of motion of the earth at its equator is about 1,038 mi/h because of its rotation. from this information, estimate the earth's circumference using an order-of-magnitude estimate. 2,000 mi 20,000 mi 200,000 mi 2,000,000 mi i just took the test and the answer is 20,000***

Picture a all traveling at a constant speed around the inside of a circular structure. is the ball accelerating? explain your answer

The magnitude of the amount of energy released by burning a fuel source, measured in energy per unit mass, is called its fuel value. note that the fuel value is the negative of the isobaric specific heat of combustion for the fuel. if all the energy obtained from burning 1.23 pounds of butane with a fuel value of 10.85 kcal/g is used to heat 128.0 kg of water at an initial temperature of 18.3 °c, what is the final temperature? note that 1 lb = 453.6 g.

Which of the following is the main energy source for the sun? a. fission of hydrogen b. fusion of hydrogen c. fusion of helium d. fission of iron