How far did you travel on this trip? What was your average speed?

Question

You decide to travel by car for your holiday visits this year. You leave early in the morning to avoid congestion on the roads. This enables you to drive at a comfortable speed of 65.0 mph for 2.84 hours. However, after this time, you unexpectedly come to a stop for 28.5 min. Traffic starts moving again and you finish your travel at 54.8 mph for an additional 1.70 hours. How far did you travel on this trip? What was your average speed? There are 1609 meters in one mile.

Answer 1

We can break the trip into three parts, calculate them, then add them up for the first part of the question. For the second part, we can use our newly found distance to get the average speed.

 

a) How far did you travel on this trip?

Trip 1:

r = 65.0 mph

t = 2.84 hours

 

r = d / t

⇒ d = rt = (65.0 mph)(2.84 hours) = 184.6 mi

 

 

Trip 2:

r = 0 mph

t = 28.5 min = 0.475 hours

 

d = rt = (0 mph)(0.475 hours) = 0 mi

 

Trip 3:

r = 54.8 mph

t = 1.70 hours

 

d = rt = (54.8 mph)(1.70 hours) = 93.16 mi

 

Total distance = Trip 1 + Trip 2 + Trip 3

= 184.6 mi + 0 mi + 93.16 mi = 277.76 mi

 

b) What was your average speed?

d_TOT = 277.76 mi
t_TOT = 2.84 hours + 0.475 hours + 1.70 hours = 5.015 hours

 

r = d / t = (277.76 mi) / (5.015 hours)

= 55.385 mph