An ant crawls in a straight line at a constant speed of $0.24 \mathrm{~m} / \mathrm{s}$ for a distance of $3.0 \mathrm{~m}$, beginning in the corner of a square classroom. It then turns exactly 90 degrees to the right and proceeds an additional $4.0 \mathrm{~m}$ with a constant speed of $0.44 \mathrm{~m} / \mathrm{s}$, reaching the other corner of the same wall from which it began. What was the ant's average speed for the full trip from corner to corner?
A) $0.21 \mathrm{~m} / \mathrm{s}$
B) $0.32 \mathrm{~m} / \mathrm{s}$
C) $0.23 \mathrm{~m} / \mathrm{s}$
D) $0.30 \mathrm{~m} / \mathrm{s}$
E) $0.34 \mathrm{~m} / \mathrm{s}$

Question

Quizplus · Accepted Answer

The average speed is calculated by dividing the total distance by the total time. The total distance is $3.0 \mathrm{~m} + 4.0 \mathrm{~m} = 7.0 \mathrm{~m}$. The time for the first part is $3.0 \mathrm{~m} / 0.24 \mathrm{~m/s} = 12.5 \mathrm{~s}$ and for the second part is $4.0 \mathrm{~m} / 0.44 \mathrm{~m/s} = 9.09 \mathrm{~s}$. The total time is $12.5 \mathrm{~s} + 9.09 \mathrm{~s} = 21.59 \mathrm{~s}$. The average speed is $7.0 \mathrm{~m} / 21.59 \mathrm{~s} \approx 0.324 \mathrm{~m/s}$, which rounds to $0.32 \mathrm{~m/s}$.

An Ant Crawls in a Straight Line at a Constant 0.24 m/s0.24 \mathrm{~m} / \mathrm{s}0.24 m/s

An Ant Crawls in a Straight Line at a Constant $0.24 \mathrm{~m} / \mathrm{s}$