Question

You drive in a straight line at 22 m/s for 12 miles, then at 30 m/s for another 12 miles. (a) How does your average speed sav compare with 26.0 m/s (the midpoint of 22 m/s and 30 m/s)

Answer 1

Answer:

Explanation:One method of calculating average speed is to divide the total distance by the total time spent

d1=d2= 12 miles

d1=d2= 19312.1 m

$t1=\frac{d1}{u1} \\t1=19312.1/22\\t1=877.8 secs$

$t2=\frac{d2}{u2} \\t2=19312.1/30\\t2=673.7 secs$

$u_a=\frac{d1+d2}{t1+t2} \\u_a=25.385 m/s$

There is slight difference between the average speeds  due to the reason that average speed is not just the midpoint of the speed but is the total distance traveled by total time.