Question

A man walks for 1 minute at a speed of $1m/s$ and then runs for 1 min at a speed of $3m/s$ along a straight track. What is the average speed of the man

Answer 1

Man walks 1 minute i.e 60 seconds at speed of $1m/s$ and runs for 60seconds at speed of $3m/s$

Given two speeds and their corresponding time taken say $s1,t1$ and $s2,t2$

then average speeed is given as $\frac{t1\times s1+t2\times s2}{t1+t2}$

We now find average speed using that formula.

Average speed = $\frac{60\times 1+60\times 3}{60+60}$

=$\frac{3+1}{2}$

So average speed is $2m/s$