Question

44. The length of a road is 380 m, correct to the nearest 10 m. Maria runs along this road at an average speed of 3.9 m/s. This speed is correct to 1 decimal place. Calculate the greatest possible time taken by Maria​.

Answer 1

The greatest possible time taken by Maria is 97.4 seconds.

Explanation:

The greatest possible time taken by Maria occurs when she moves at constant rate and is equal to the length of the road divided by the length of the road. That is to say:

`t = (\Delta s)/(v)`

Where:

`\Delta s` - Length of the road, measured in meters.

`v` - Average speed, measured in meters per second.

Given that
`\Delta s = 380\,m` and
`v = 3.9\,(m)/(s)`, the greatest possible time is:

`t = (380\,m)/(3.9\,(m)/(s) )`

`t = 97.4\,s`

The greatest possible time taken by Maria is 97.4 seconds.