A car travels 400 miles in 7 hours. What is its average speed?
The average speed is 57.142857 mph.
How to work it out
- 1
Write down what you know: distance d = 400 miles, time t = 7 hours. You are asked for the speed v.
- 2
Use the formula speed = distance ÷ time:
- 3
Answer with the unit: 57.142857 mph.
- 4
The same formula rearranged: distance = speed × time (57.142857 × 7 = 400 miles) and time = distance ÷ speed (400 ÷ 57.142857 = 7 hours).
LaTeX source of the formulas on this page
\[ v = \frac{d}{t} = \frac{400}{7} = 57.142857\ \text{mph} \]
\[ v = \frac{d}{t} = \frac{400}{7} = \frac{400}{7} = 57.142857 \]How far at 57.142857 mph
| Time | Distance |
|---|---|
| 0.5 hours | 28.571429 miles |
| 1 hour | 57.142857 miles |
| 2 hours | 114.28571 miles |
| 3 hours | 171.42857 miles |
| 4 hours | 228.57143 miles |
| 5 hours | 285.71429 miles |
Questions
What is the speed if a car travels 400 miles in 7 hours?
The average speed is 57.142857 mph.
How far does it go in 3 hours at that speed?
171.42857 miles.