Problema Solution
Two streetcars aer 11 miles apart and traveling toward each other on parallel tracks. They meet at 12 minutes. Find the speed each streetcars if one travels 15 miles per hour faster than the other.
Answer provided by our tutors
let
v1 = the speed of the first street car
v2 = the speed of the second street car
d = 11 mi the distance between the cars
t = 12 min = 12/60 hr = 1/5 hr the time of the travel
since speed = distance/time we have distance = speed*time
the distance traveled by the first car + the distance traveled by the second car = the total distance
v1*t + v2*t = d
t(v1 + v2) = d
(1/5)(v1 + v2) = 11 multiply both sides by 5
v1 + v2 = 55
one travels 15 miles per hour faster than the other:
v2 = v1 + 15
by solving the system of equations:
v1 + v2 = 55
v2 = v1 + 15
we find:
v1 = 20 mph
v2 = 35 mph
click here to see the step by step solution of the system of equations:
the speed of the first car is 20 mph.
the speed of the second car is 35 mph.