Measuring Speed Flashcards
All 5 cards in this deck
What are the steps to measure the average speed of a toy car in the laboratory using a stopwatch?
e.g. a car rolling along a bench
- Measure the distance between two marks
- Start the timer at the first mark, stop it at the second
- speed = distance ÷ time; repeat and average
How does a single light gate with a card on a trolley measure the trolley's speed?
The card interrupts the light beam; speed = width of the card ÷ time the beam is blocked.
What is the main advantage of using light gates instead of a hand-held stopwatch?
They remove human reaction time (about 0.2 s), which is similar in size to the short times being measured.
How is ticker tape used to find the speed of a trolley?
Measure the distance between dots; the timer makes dots at a known rate (e.g. 50 per second), so speed = distance ÷ time.
Give two ways to improve a measurement of average speed made with posts and a stopwatch.
Increase the distance between the posts, and use an electronic timer or light gates (also: use marks on the track, stand midway between the posts).