Suppose you are a roofer and you find yourself teetering on the edge of a house with a heavy hammer in your hand. As you are about to fall, you remember that throwing the hammer can propel you backward. What physics law did you remember could save you

An electron moves with a constant horizontal velocity of 3.0 × 106 m/s and no initial vertical velocity as it enters a deflector inside a tv tube. the electron strikes the screen after traveling 26 cm horizontally and 19 cm vertically upward with no horizontal acceleration. what is the constant vertical acceleration provided by the deflector? (the effects of gravity can be ignored.)