Question 665705
First car (car1) speed {{{v[1] = x (km/h)}}}
Second car (car 2) speed {{{v[2] = y( km/h)}}}

second car passes the lad mark 1 hour later:
 in one hour car 2 has passes {{{d= x km}}}


They are traveling in same direction
to catch up speed: {{{v[2]-v[1]= y-x (km/h)}}}

to catch up distance: {{{d= x km}}}

to catch up time {{{t= (x / (y-x)) h}}}