How long would it take to drive 102 miles at 65 miles per hour?

Answer 1

Given:

• a speed (s) of 65 mph (miles/hour)
• a distance (d) of 102 miles

Assumptions:

• What is given, assumes a constant (or average) speed.

Formulas:

• average speed (s) = distance (d) / time (t)
  s = d/t

Rewrite the formula in terms of time:
s = d/t
(s)(t) = (d)(t)/t
st = d

st/s = d/s

t = d/s
so time equals the distance divided by speed

Plug the known values into the variables:

t = d/s

t = (102 miles) / (65 miles / hour)

t ~= 1.6 hours (rounded to two sig figs)

To convert time to something more meaning full:

1.6 hours - 1 hour = 0.6 hour (remove the one hour, add it at the end)

(0.6 hour) ( 60 minutes / hour ) = 36 minutes

1.6 hours = 1 hour and 36 minutes