# Physics coursework - marked A* (60/64marks)

6847 words 28 pages
The factors that affect the motion of a falling object
Scientific Knowledge
When an object falls, many forces are acted upon it: gravity, friction, air resistance and, if in the water, up thrust. When an object starts to fall, gravity over powers air resistance, however, as an object starts to reach terminal velocity (its maximum speed) the opposite forces start to even out until they are equal. Some people believe that if the forces are balanced then the object has stopped moving, meanwhile they could also just be moving at a constant speed (its terminal velocity). All free-falling objects accelerate at the same speed no matter what their mass is (9.8m/s²).
There are two calculations you need for this investigation, no matter which

There are more factors that can affect the motion of a falling object; however these four that I have included in my scientific knowledge are the four main ones.

Preliminary Tests
Preliminary experiments are used to ascertain what materials used and why, what ranges we will have and why, and what variables there are and how they can be controlled. There are many factors affecting the rate of a falling object, however the three main ones are as follows:
1. Weight of the object (mass or gravity).
2. Surface area of the object or its’ parachute surface area.
3. Viscosity of the material it is falling through.
There are two methods that are available to us at school: the Parachute method, and the Ball Bearing method.
The Parachute method involves dropping an object with a parachute attached to it and timing how long it takes to hit the ground; while the Ball Bearing method involves dropping a metal ball into a measuring cylinder full of glycerol and timing how long it takes to reach a certain point. I am going to use the Parachute method because it is a quicker method and the science department at our school have an endless list of the supplies needed for it. Meanwhile, I am not using the Ball Bearing method because we as a school have a very limited supply of glycerol and we cannot remove the ball bearing very easily afterwards.
There are two variables (factors) we are able