Does an object, when thrown down, bounce back because of the normal force?

Question

But isn't it equal to the weight? So why does it move up, shouldn't they balance out?

Answer 1

The magnitude of the normal force equals the magnitude of the weight but the direction is opposite. (force is a vector). So if positive direction is downwards weight = 10N but the normal force (when the object touches the surface) is -10N.

So when a ball is dropped the instant it hits the ground there is a force pair - the weight of the ball downwards and the normal force upwards. The normal force upwards causes the ball to bounce.