A sports commentator is trying to predict the winning margin,
t seconds, of racing driver A over his nearest rival B. Use this information to calculate t and |
To predict the value of t, we need to use the formula:
Distance = Average Speed × Time |
We can work out the times taken by each driver and subtract to find t.
This translates into 52 min 10.43 sec
An equivalent calculation gives 52 min 16.12 sec
Subtracting times gives t = 5.68 seconds.
Driver A's speed has been rounded to 220.8 km per hour.
The actual speed could lie between 220.75 and 220.8499999... kmph.
(A speed below 220.75 would be rounded down to 220.7;
A speed of 220.85 or above would be rounded up to 220.9)
In practice, we quote the limits as 220.75 and 220.85 kmph
The table shows the limits of accuracy for the other measurements.
Speed of A | Speed of B | Length of Circuit | |
Greatest | 220.85 | 220.45 | 3.845 |
Least | 220.75 | 220.35 | 3.835 |
The greatest value of t occurs when:
This works out to be 7.11 seconds.
The least value of t occurs when:
This works out to be 4.22 seconds.