car passes a landmark on the highway travelling at a constant rate of 40 km/h two hours later a second car passes the same landmark travelling in the same direction at 65 km/h how much time after the second car passes the landmark will overtake the first car

Respuesta :

recall your d = rt, distance = rate * time

the faster car of 65km/h, will "overtake" the first car.... when they both have are next to each other, and when that happens, the distance covered by both, is exactly the same, let's say the first car is A and the second is B

by the time car B catches up to car A, car A has covered "d" kilometers, and car B has to had covered "d" kilometers as well by then

if say... car A took off at "t" time, car B took off 2hrs later, or " t + 2 "

thus   [tex]\bf \begin{array}{lccclll} &distance&rate&time\\ &-----&-----&-----\\ \textit{car A}&d&40&t\\ \textit{car B}&d&65&t+2 \end{array} \\\\\\ \begin{cases} \boxed{d}=40t\\ d=65(t+2)\\ ----------\\ \boxed{40t}=65(t+2) \end{cases}[/tex]

solve for "t"