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.

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.

Common misconception