A 2.5 kg ball moving at 5 m/s collides with a 2.5 kg stationary ball in a perfectly elastic collision.  What is the velocity of the second ball before the collision? ​

What cultural factors do geographers consider when they study human geography? climate patterns customs elevations ethnicity language religion

When an imperial power has political control, what is the territorial called

Four score and seven years ago our fathers brought forth on this continent a new nation, conceived in liberty, and dedicated to the proposition that all men are created equal. —"the gettysburg address," abraham lincoln which quotation correctly uses an ellipsis to shorten lincoln’s words?