Question

Calculate the speed of the car at each checkpoint by dividing the distance between each checkpoint in meters by the change in time. Record your answers in Table C of your Student Guide.

The speed at the first quarter checkpoint is
m/s.

The speed at the second quarter checkpoint is
m/s.

The speed at the third quarter checkpoint is
m/s.

The speed at the finish line is
m/s.

Answer 1

I don’t have the times or distances from your Student Guide, so I can’t give the numeric answers yet. Here’s how to get them and an example so you can fill Table C.

Method/formula
- Let L = total distance (m). Each quarter distance = L/4.
- Let t1, t2, t3, t4 be the times (s) when the car passed the 1st quarter, 2nd quarter, 3rd quarter, and finish respectively.
- Speeds (m/s):
- first quarter: v1 = (L/4) / t1
- second quarter: v2 = (L/4) / (t2 − t1)
- third quarter: v3 = (L/4) / (t3 − t2)
- finish: v4 = (L/4) / (t4 − t3)

Example
- If L = 100 m and times are t1 = 2.5 s, t2 = 5.1 s, t3 = 7.8 s, t4 = 10.2 s:
- each quarter = 25 m
- v1 = 25 / 2.5 = 10.00 m/s
- v2 = 25 / (5.1 − 2.5) = 25 / 2.6 ≈ 9.62 m/s
- v3 = 25 / (7.8 − 5.1) = 25 / 2.7 ≈ 9.26 m/s
- v4 = 25 / (10.2 − 7.8) = 25 / 2.4 ≈ 10.42 m/s

If you post the total distance and the four checkpoint times (or the times in your Table C), I’ll calculate the four speeds for you.