Q1.
The magnitude of average acceleration of cars is generally specified as the time taken by the car to go from 0 km h⁻¹ to 100 km h⁻¹. Look it up on the internet and find this time for various cars, and record those in Table 4.2.
Answer
First convert the change in speed into SI units, because the acceleration must come out in m s⁻².
change in speed = 100 km h⁻¹ − 0 km h⁻¹ = 100 km h⁻¹
100 km h⁻¹ = 100 × 1000 m / 3600 s = 27.8 m s⁻¹
100 km h⁻¹ = 100 × 1000 m / 3600 s = 27.8 m s⁻¹
Now look up the "0–100 km h⁻¹" time quoted by the manufacturer or a road test for each car and fill the middle column. Typical published values look like this — treat them as a model; the whole point of the activity is that you find and record real figures yourself.
| Car type | Time interval during which the speed goes from 0 to 100 km h⁻¹ (s) | Magnitude of average acceleration (m s⁻²) |
|---|---|---|
| Small hatchback | 12.0 | 2.3 |
| Mid-size sedan | 10.0 | 2.8 |
| SUV (turbo-petrol) | 8.5 | 3.3 |
| Electric hatchback | 7.0 | 4.0 |
| Sports car | 3.5 | 7.9 |
Tip: keep the third column to two significant figures. The published 0–100 time is itself only quoted to about a tenth of a second, so quoting the acceleration to three decimals would be false precision.