Question

A student ran the 100-m dash in 15.4 s. What was the student’s speed in miles per hour?

Answer 1

15.4 seconds = 0.00428 hours and 100 meters = 0.062 miles soo the student ran approximately 14.5 mph

Answer 2

Speed of the student was 14.51 miles per hour.

Explanation:

A student ran the dash = 100 m

Since 1 meter = 0.000621 miles

Therefore, 100 meter = 100× 0.000621

= 0.0621 miles

He ran the dash in 15.4 seconds

∵ 3600 seconds = 1 hour

∴1 second =
`(1)/(3600)` hour

∴ 15.4 seconds =
`(15.4)/(3600)` hour

= 0.00428 hours

Now we know the formula to calculate the speed

Speed =
`\frac{\text{Disatance}}{\text{Time}}`

=
`(0.0621)/(0.00428)` miles per hour

= 14.51 miles per hour

Speed of the student was 14.51 miles per hour.