Problema Solution
A truck enters the freeway and drives south at 55 mph. Ten minutes later a car enters the freeway at the same entrance as the trick did and drives south at 70 mph. How long after the car enters the freeway will it catch up to the truck?
Answer provided by our tutors
let
v1 = 55 mph the speed of the truck
v2 = 70 mph the speed of the car
t = the time that the car needs to catch up the truck after it enters the freeway
t + 10/60 = the time of truck until the car catches up
we will use the formula speed = distance/time = > distance = speed*time
since both, the car and the truck pass the same distance we have
v1*(t + 10/60) = v2*t
55(t + 1/6) = 70t
by solving we find
t = 55/90
t = 11/18 hr
click here to see the step by step solution of the equation
t = (11/18)*60 min
t = 36.7 min
the car will catch up to the track 36.7 min after it enters the freeway.