(a) What is the gravitational potential energy of a two-particle system with masses 8.2 kg and 6.9 kg, if they are separated by 1.8 m

When you hold a rectangular object, how does the area of the side that is resting on your hand affect the pressure and the force that the object exerts?

Which of the following conditions lead you to see an absorption line spectrum from a cloud of gas in interstellar space? the cloud is extremely hot. the cloud is visible primarily because it reflects light from nearby stars. the cloud is cool and lies between you and a hot star. the cloud is cool and very dense, so that you cannot see any objects that lie behind it.

Calculate 9 ∙ 10-5 divided by 3 ∙ 10-9. (box after the "10" in answer is for the