Answer:
<u>20 Minutes</u>
<u></u>
Explanation:
Well we know Mph (Miles per hour) is distance over time : 
R (rate) = 60
d (distance) = 20
t (time) = Unknown
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
R =
↓
60 =
↓
t = 
↓
t =
or 0.3333
<em>So basically it would take one third of an hour. Lets change these units to minutes.</em>
60 * 0.333333 = 20
<em>So it would take you </em><u><em>20 minutes</em></u><em> to drive 20 miles on a bus that drives 60 mph</em>
<em />
Hope that helps
<em>~Siascon~</em>
The correct answer for this question is this one: "measuring the temperature increase of water from doing work stirring it." This experiment is generally regarded as being first carried out by James Joule is this one, <span>measuring the temperature increase of water from doing work stirring it.</span>
It is true that Gustav Theodor Fechner was the finder of <span>psychophysics. </span>
Physical change 1 is the answer