A coin is dropped from a height above the ground. Which three statements are correct? -If you double the height that you drop the coin from, you double the gravitational potential energy.
-You would have to drop it from a height that is nine times bigger to treble the speed when it hits the floor.
-If you double the height that you drop the coin from, you quadruple the gravitational potential energy.
-If you double the height that you drop a coin from, you double the speed at which it hits the floor.
-If you quadruple the height that you drop a coin from, you double the speed at which it hits the floor.

Is a  vector quantity  that refers to "the rate at which an object changes its position." imagine a person moving rapidly - one step forward and one step back - always returning to the original starting position. while this might result in a frenzy of activity, it would result in a zero velocity. because the person always returns to the original position, the motion would never result in a change in position. since velocity is defined as the rate at which the position changes, this motion results in zero velocity. if a person in motion wishes to maximize their velocity, then that person must make every effort to maximize the amount that they are displaced from their original position. every step must go into moving that person further from where he or she started. for certain, the person should never change directions and begin to return to the starting position.

If football was tossed in air without gravity or friction the ball would go into space

An atom's smaller negative particles are at a distance from the central positive particles, so the negative particles are easier to move.