Gravity isn’t pulling other objects toward me because I haven’t given my force either or have made an action. According to Newton’s Third Law, there needs to be an action, in order for an opposite reaction. For example, if I reach over to the pencil and grab it, then the reaction will occur.

Your weight on the Moon is 16.5% what you would experience on Earth. In other words, if you weighed 100 kg on Earth, you would weigh a mere 16.5 kg on the Moon. For you imperial folks, imagine you tipped the scales at 200 pounds. Your weight on the Moon would only be 33 pounds.

Due to its greater mass, the elephant also experiences a greater force of gravity. That is, the Earth is pulling downwards upon the elephant with more force than it pulls downward upon the feather.

As we walk on the surface of the Earth, it pulls on us, and we pull back. But since the Earth is so much more massive than we are, the pull from us is not strong enough to move the Earth, while the pull from the Earth can make us fall flat on our faces.

The answer is gravity: an invisible force that pulls objects toward each other. Earth’s gravity is what keeps you on the ground and what makes things fall. Anything that has mass also has gravity. Objects with more mass have more gravity.

Newton’s third law of motion is naturally applied to collisions between two objects. In a collision between two objects, both objects experience forces that are equal in magnitude and opposite in direction. Such forces often cause one object to speed up (gain momentum) and the other object to slow down (lose momentum).

How did the speed of the marble that comes off the end of the line change as you increased the speed of the marble that travels down the chute? Therefore, the speed of the marble that came out increased as well.