Some force and motion experiments include dropping two objects of different masses from the same height to demonstrate Newton’s law of acceleration, and the terminal velocity experiment to demonstrate the interaction of the effect of drag or resistance on acceleration. Two objects with different masses dropped from the same height reach the ground at the same time.
Even though the heavier object has greater force pulling it toward the earth, the additional mass also resists acceleration to the same degree as its mass, so the objects fall at the same rate anywhere on earth.
The terminal velocity experiment proves that a falling object reaches a maximum rate of acceleration as it falls due to resistance. The experiment entails dropping balls of different diameters through a viscous solution in a long cylinder marked at equal distances. Normally, gravity should cause a ball to accelerate as it nears the bottom. In other words, the ball should drop faster between the end markers than it does at the middle or starting markers. However, timing the ball at different markers reveals that it reaches a speed at which the time between segments becomes equal, or reaches its terminal velocity, the maximum speed it can attain.
This effect occurs due to the force of drag, or resistance caused by the viscosity of the liquid counteracting the gravitational pull that causes the ball to fall. By dropping a larger object with the same weight, it is possible to demonstrate that the terminal velocity is not a function of mass, but of area. This is why a man wearing a parachute falls to the ground more slowly than a man without one.