Question

1. jackie drove 122 miles from her house in grand rapids, michigan to her friends house in ann arbor, michigan. she left her house at 9:25 am and arrived at 11:15 am.

a. do you think jackie drove at a constant speed from grand rapids to ann arbor? explain why or why not.
b. what was jackies average speed, in miles per hour? round to the nearest hundredth.
c. what information would you need to know to be able to determine about how fast jackie was driving at exactly 11 am?

Explanation:

Step1: Calculate time elapsed

First, find the time from 9:25 AM to 11:15 AM. 11:15 - 9:25 = 1 hour and 50 minutes. Convert 50 minutes to hours: 50/60 = $\frac{5}{6}$ hours. So total time $t=1+\frac{5}{6}=\frac{6 + 5}{6}=\frac{11}{6}$ hours.

Step2: Calculate average speed

The formula for average speed $v=\frac{d}{t}$, where $d = 122$ miles and $t=\frac{11}{6}$ hours. So $v=\frac{122}{\frac{11}{6}}=122\times\frac{6}{11}=\frac{732}{11}\approx66.55$ miles per hour.

Step3: Answer part c

To find the speed at exactly 11 AM, we would need to know the distance traveled from the start - point to the position at 11 AM and the time taken to reach that position (from the start - time to 11 AM).

Answer:

a. No, in real - world driving, there are stops, slow - downs at traffic lights, etc.
b. 66.55 miles per hour
c. The distance traveled from the start to 11 AM and the time taken from the start time to 11 AM.