Question

A police jeep is chasing a culprit going on a motorbike . The motorbike crosses a turning at a speed of $72km/hr$. The jeep follows it at a speed of $90km/h$, crossing the turning ten seconds later than the bike. Assuming that they travel at constant speeds, how far from the turning will the jeep catch up with the bike?

Answer 1

$V_p=90km/h=25m/s$.
$V_c=72km/h=20m/s$.
In $10sec$ culprit reaches at point $B$ from $A$.
Distance converted by culprit $S=vt=20\times 10=200m$.
At time $t=10sec$ the police jeep is $200m$ behind the culprit.
Time $=s/v=200/5=40s$. (Relative velocity is considered).
In $40s$ the police jeep will move from $A$ to a distance $S$, where $S=vt=25\times 40=1000m=1.0km$ away.
$\therefore$ The jeep will catch up with a bike, $1km$ far from the turning .