Answer to Question #153167 in Mechanics | Relativity for Juju

Question

Arnold and Juju are 140 m apart. Arnold can run at a speed of 8 m/s while Juju can run at a speed of 6m/s. If the two boys run at the same instant, straight towards each other, when and where will they meet?

Answer 1

They approach each other with a speed $v=v_{Arnold}+v_{Juju} = 8+6=14 m/s$ . Therefore, time when they meet is $t = \frac{distance}{velocity} = \frac{140}{14} = 10s$ , 10 seconds. During this time, Arnold will run $10*8 = 80m$ from his initial position, so that's where they will meet (we can equivalently say that they will meet 60m from Juju's initial position).