SOLUTION: Given: d = rt, where "d" is distance, "r" is rate, and "t" is time. One car leaves point A and travels due north at 50 mi/hr. Another car leaves point A 3 hours later and

Algebra ->  Customizable Word Problem Solvers  -> Travel -> SOLUTION: Given: d = rt, where "d" is distance, "r" is rate, and "t" is time. One car leaves point A and travels due north at 50 mi/hr. Another car leaves point A 3 hours later and      Log On

Ad: Over 600 Algebra Word Problems at edhelper.com


   



Question 874284: Given: d = rt, where "d" is distance, "r" is rate, and "t" is time.
One car leaves point A and travels due north at 50 mi/hr. Another
car leaves point A 3 hours later and travels due south at 70 mi/hr. When
will the two cars be 1,000 miles apart?

Answer by josgarithmetic(39620) About Me  (Show Source):
You can put this solution on YOUR website!
Two cars going in opposite directions but leave at different times, three hour difference.
_______________speed_________time_________distance
NORTH__________50_____________t___________
SOUTH__________70____________t-3__________

I am making all numbers into variables, because you asked a very similar question in a very recent help request post, and you may find the solution process very much alike in both questions.


When are the two cars a difference of m miles from eachother?
Southbound car left k hours after the north bound car.
_______________speed_________time_________distance
NORTH__________n_____________t_____________nt
SOUTH__________s____________t-k____________s(t-k)
Distance Apart_____________________________m

Unknown variables are t. Given variables with values assumed to be n, s, k, and m.

Solution Continuation:
highlight_green%28nt%2Bs%28t-k%29=m%29
nt%2Bst-sk=m
nt-st=m%2Bsk
t%28n-s%29=m%2Bsk
highlight%28t=%28m%2Bsk%29%2F%28n-s%29%29