Answer to Question #227140 in Classical Mechanics for King

Question

Two athletes a and b set off from the same point but in opposite directions at a constant speed around a track of circumference 400m.if they meet after 50 s and the speed of a is 1.5 times the speed of b.calculate the speed of each

Answer 1

Let the speed of athlete B is $v$, then speed of of athlete A is $1.5v$. We get

$$l=v_At+v_Bt=2.5vt$$

Hence,

$$v=l/2.5t=400\:\rm m/(2.5*50\: s)=3.2\: m/s$$

Finally

$$v_B=3.2\: {\rm m/s}\\ v_A=1.5*3.2\: \rm m/s=4.8\:\ m/s$$