A person holds a 4.0 kg block at position A shown above on the left, in contact with an uncompressed vertical spring with a spring constant of 500 N/m. The person gently lowers the block from rest at position A to rest at position B. Which of the following describes the change in the energy of the block-spring-Earth system as a result of the block being lowered?

A14 kg rock starting from rest free falls through a distance of 5.0 m with no air resistance. find the momentum change of the rock caused by its fall and the resulting change in the magnitude of earths velocity. earth mass is 6.0 * 10^24 kg. show your work assuming the rock earth system is closed.

How does an increase in temperature generally affect the rate of a reaction?

Regarding the history of the universe, which of the following is true? all the chemical elements were created during the big bang, but some have been modified since that time as a result of radioactive decay. the earth formed quickly after the big bang. all the current stars in our galaxy formed about the same time billions of years ago. key elements of which earth and life are made, including carbon, oxygen, and iron, did not exist when the universe was born and were created later in stars.