Hometest help (fixed) If i drill a hole through the center of the earth that cross the entire planet and then i drop a ball into the hole: 1. What is going to be the speed of the ball at the other end of the planet? 2. How much time is going to take the ball of going from one end to another? When the ball reach the core there will be a balance in forces and the kinetic energy will transform in potential energy again, thats why the ball will move to the other end of the planet and not stop in the core. I think the speed at the end of the planet is going to be 0 m/s because it would had reached a max altitude and the gravity will pull the ball down the hole again. I'm still having problems finding the time, i think it has to do with gravitational attractions. Any help will be welcome.