Question

A person takes a trip, driving with a constant speed of 89.5km/h, except for a 22min rest stop. If the person's average speed is 77,8km/h (a.) how much time is spent on the trip and (b.) how far does the person travel?
Need help finding the starting point to this equation

Answer 1

To start off, we have to find the difference between 89.5 and 77.8, which is 11.7. 11.7/89.5 is the fraction of the total time spent on the trip, so 22*89.5/11.7 is the total time spent which is about 168.29 minutes. to find how long the person travels for, we first have to find the average speed per minute, which is 77.8/60. After that, we multiply that by the answer we got for the time which in total approximately equals 218.22 miles

Answer 2

Answer:

Part a)

$t = 147.8 min$

Part b)

$d = 220.2 km$

Explanation:

Speed of the trip of the person is given as

$v = 89.5 km/h$

here let say the time taken by the person for the trip is "t" min

so the total distance moved by the person in above time is given as

$d = (89.5)\times \frac{t}{60}$

so we will have

$d = 1.49 t$

now the average speed for the whole trip is given as

$v_{avg} = \frac{distance}{time}$

$time = t + 22 min$

now we have

$v_{avg} = \frac{1.49 t}{\frac{(t + 22)}{60}}$

now we have

$77.8 = \frac{1.49 t}{\frac{(t + 22)}{60}}$

$1.2967(t + 22) = 1.49 t$

$0.193 t = 28.53$

$t = 147.8 min$

Part b)

Total distance moved by the person is given as

$d = 1.49 t$

$d = 1.49(147.8)$

$d = 220.2 km$