A cart sitting at the top of a hill has 9000 J of potential energy. The cart is then pushed and by the time it is half way down the hill it has converted half of its potential energy . If the carts weighs 1000 kilograms then how fast is the cart rolling when it is halfway down the hill?

An electron is ejected into a horizontal uniform e⃗ field at a parallel horizontal velocity of v0. assume the electron's initial position x0, initial velocity v0, time t, magnitude of electric field e, electron's mass m, and the magnitude of the electron's charge |e|. ignore the force that earth exerts on the electron. assume the e⃗ field is in the same direction as the initial velocity. part a define the equation for the electron's velocity. express your answer in terms of the variables v0, |e|, t, e, and m.