Key learning points

1. A dynamics trolley speeds up (accelerates) along the whole length of a steep ramp.
2. Instantaneous speed is the average speed over a very short time period.
3. Taking measurements by reading the timing lines at eye level improves accuracy.
4. Repeated readings by different observers helps to check for systematic errors.

Common misconception

Keywords

• Repeatable - A measurement is repeatable if the same (or similar) results are obtained when the same person repeats the investigation using the same method.

• Reproducible - A measurement is reproducible if the same (or similar) results are obtained when the same person repeats it using a different method, or a different person repeats it using the same method.

• Instantaneous speed - The instantaneous speed of an object is its speed at a particular moment in time.

• Directly proportional - If two variables are directly proportional, when one variable increases, the other increases at the same rate.