Does Newton’s Second Law, explain that force truly does equal mass multiplied by acceleration?
No, I think the author is confused about a few things. I’ve seen a lot of kids’ science poorly explained. First, your little experiment will *confirm* or *test* Newton’s Second Law but not PROVE it — let’s not, however, quibble over semantics and philosophy. This rings vaguely familiar as one of Einstein’s thought experiments where you can’t tell whether you’re (1) standing in an elevator at rest on the earth OR (2) accelerating up or down at 1 g but away from actual gravity — demonstrating the equivalence principle, which is more or less assumed here and not directly relevant. In this experiment the elevator is both accelerating AND feeling earth’s gravity, making it a complicated system indeed. Speaking of the elevator working with or against gravity only confuses the issue further. The elevator at rest has zero acceleration. Once moving upward or downward between floors, it also has zero acceleration. It’s those brief moments at the start and stop where the action is. Acceleration
PURPOSE The purpose of this lab is to prove that Newton’s second law of motion is true. Newton’s second law states that the net force of an object is equal to its mass multiplied by its acceleration. In our case the net force of the object is its weight which is equal to the mass of the object multiplied by the acceleration due to gravity on earth. By the elevator accelerating up and down, we will see changes in the object’s weight on the scale. At rest the object will have its normal weight. As the elevator begins to accelerate downwards the weight of the object should decrease because the object is moving with the force of gravity. As the elevator accelerates upwards, the weight should increase because it is working against the force of gravity. MATERIALS (See Enclosure One) PROCEDURE 1. Obtain the 100 gram mass and a digital scale. Weigh the mass to ensure your accuracy. 2. Go to the elevator and place the scale on the floor along with the 100 gram mass on top of that. 3. The instan
