Question

question 2 (1 point)
a motorist travels 160 km at 80 km/h and 160 km at 100 km/h. what is the average speed of the motorist for this trip?
84 km/h
89 km/h
90 km/h
91 km/h
page 2 of 20

Explanation:

Step1: Calculate the time for each part of the trip

Use the formula \(t=\frac{d}{v}\).
For the first part: \(t_1=\frac{160}{80}=2\) hours.
For the second part: \(t_2=\frac{160}{100}=1.6\) hours.

Step2: Calculate the total distance and total time

Total distance \(d = 160+160=320\) km.
Total time \(t=t_1 + t_2=2 + 1.6=3.6\) hours.

Step3: Calculate the average speed

Use the formula \(v_{avg}=\frac{d_{total}}{t_{total}}\).
\(v_{avg}=\frac{320}{3.6}\approx89\) km/h.

Answer:

89 km/h