Let's begin by determining the equilibrium position of a seesaw pivot. you and a friend play on a seesaw. your mass
90 kg, and your friend’s mass is 60 kg. the seesaw board is 3.0 m long and has negligible mass. where should the pivot be placed so that the seesaw will balance when you sit on the left end and your friend sits on the right end?

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.)