Aball on a cart is moving at a rate of 2 m/s. the cart suddenly stops and the ball continues to travel in the same direction at the same speed. this is an example of which newton’s laws?

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.)