Students are introduced to the force of gravity, and see that objects fall at the same rate, even if their masses are different.
Although gravity pulls harder on big, heavy objects, they're harder to get moving than light ones. Therefore, objects that are the same shape will fall at the same rate, even if one weighs more than another. Shape can make things tricky because big, flat, light objects (like a flat sheet of paper) are slowed down more by air resistance than are smaller, smoother objects.
- Gravity: The forces of attraction which the Earth has for objects on its surface; also the force of attraction between any two objects.
- Friction: The resistance a body meets when moving over a surface or through a gas or liquid; the force that resists the motion of two surfaces that are touching each other.
- Air Resistance: The friction caused by an object moving through air.
- Drafting: A technique used in sports, where an athlete or car races behind someone else to take advantage of the reduction of air pressure/resistance.