Question 1046965


Jack wants to derive a formula he could use to calculate his total journey time. 


He decides to use T to represent total time, t to represent the time he spends actually driving, b to represent the time for breaks and rests, d to represent the total distance traveled, s to represent the average speed in miles per hour.


T, t, and b, are measured in hours.
d is measured in miles.
s is measured in miles per hour.


He knows that t is equal to d divided by s. 


Derive a formula to calculate T in terms of b, d and s.


T = t + b


this means that the total time is equal to the time spent driving plus the time spent on breaks.


since rate * time = distance, you get s * t = d.
solve for t to get t = d/s.


formula of T = t + b becomes T = d/s + b