g. 1.5km) whereas displacement is a direct line which connects from the start point of an objects, measuring the change of position of a moving body. Displacement is a vector quantity which states the length and direction (e.g. 500m north). Similarly to distance and displacement, speed and velocity are often used in replacement of each other, when in fact, they are different. Velocity is the rate of change in displacement, thus making it a vector quantity. Speed is a measure of how quickly something moves, and can be categorised into instantaneous speed, and average speed. Averaged speed is more commonly used and can be calculated by the formula speed = or v= (where v= speed or velocity, s= displacement or distance and t= time).
Velocity time graphs are a common way of displaying data, when you have displacement and time data, using the velocity formula makes the 2 sets of data 1 set of more meaningful data (see figures 1, 2 and 3 below). By looking at figures 1, 2 and 3, it is easy to tell that the steeper the line, the greater the acceleration. When the line is horizontal, the velocity is constant.
Method Part A.
1. A single pulley attached to a block of wood was clamped to the edge of a bench top. .
2. A 400g trolley truck was attached to a piece of string which was then fed through the single pulley.
3. The remaining end of the string that was fed through the pulley was tied to 300N, then hung off the side of the bench top slightly and not touching the ground, as high up and close to the bench top as possible. .
4. At the other end of the bench, a ticker timer was assembled attached to a power pack plugged into a power source.
5. The bench was measured and ticker timer tape was cut into a strip to match the length of the bench.
6. Ticker timer paper tape was fed through the ticker timer and attached to the other end of the trolley truck. .
7. The trolley truck was held onto as high up and close to the ticker timer as practical until the investigators were prepared to launch the experiment.
