Question

A car is moving down a highway at -15 m/s and accelerating at 3 m/s^2. If it's initial position is at x = 0 m where will it be after 3 seconds?

Answer 1

Standing at the edge of a cliff 240 m tall. You throw a ball into the air one directly upward at 5 m/a and another downward at -5 m/s. Use conservation energy to show that they will have the same speed at the bottom.

I know I have to do it twice.. And it should seem simple. I think I'm over thinking it. I know I need to use KEi+Ui=KEf+Uf