A runner covers the first half of a 10\text{km} run at 4\text{m/s} and the second half at 6\text{m/s}. What is the average speed for the entire run?

4.8\text{m/s} Total distance / total time: \bar v = 2 v1 v2 / (v1 + v2) = 2(4)(6)/(4+6) = 48/10 = 4.8\text{m/s} (the harmonic-mean shortcut for equal-distance halves).

school

Acemy

Displacement, Velocity, and Acceleration

AP Physics 1· difficulty 3/5

10~\text{km}

A
$10~\text{m/s}$
B
$5.0~\text{m/s}$
C
$5.2~\text{m/s}$
D
$4.8~\text{m/s}$
check_circle

Explanation

/

Want 10 more like this — adaptive to your weak spots?

Practice 10 like thisarrow_forward Predict my AP score

Related questions