Question

A bug travels at the rate of 3.0 miles per hour. How fast is this in um/nsec? Hint: 2.54cm = 1 inch and 1 mile = 5,280 feet

Answer 1

Note that
1 mi = 1609.34 m = 1609.34 x 10⁶ um
1 h = 3600 s = 3600 x 10⁹ ns

Therefore the speed of the bug is
(3.0 mi/h)*(1609.34x10⁶ um/mi)*(1/3600x10⁹ h/ns)

`(3.0 \, (mi)/(h)) (1609.34*10^(6)\, (um)/(mi) )( (1)/(3600* 10^(9)) (h)/(ns) ) =1.34\,* 10^(-3) \, (um)/(ns)`

Answer:
`1.34 * 10^(-3) \, (\mu m)/(ns)`