A cliff jumper runs off a 15m high cliff. Rocks extend 3.0m past the cliff bottom. We can ignore air resistance. What is the minimum horizontal velocity needed to clear the rocks?

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.)