Force; Gravity, Weight and Free Fall
Why things fall, what a force really is, and how heavy you are.
Big Idea: A force is simply a push or a pull. The Earth pulls every object toward itself with a force we call gravity. That is why a dropped apple falls, why a ball comes back down, and why you have a weight.
By the end of this lesson you will be able to:
- say what a force is and name its unit, the newton (N);
- explain that the Earth attracts every body (gravity);
- describe free fall and use the value g = 9.8 m/s2;
- find the force of gravity with the formula F = mg;
- tell the difference between weight and mass;
- explain the idea of weightlessness.