physics
posted by ruby .
earlier in this forum, marina asked the same question as i did. unfortunately, someone did answer, very clearly, but for some reason i remained to be a little lost. Here is the question:
A car traveling 90 km/h is 100 m behind a truck traveling 75 km/h. How
long will it take the car to reach the truck?
Can someone pleasee tell me the answer to this problem and HOW they solved it. THANK YOU!! =)

I don't know physics, but I can show you one way to solve this problem.
First, let's find how many meters each vehicle covers in one minute.
90 km/h = 90,000 m/h = 1500 m/minute
75 km/h = 75,000 m/h = 1250 m/minute
1500  1250 = 250 meters
100/250 = 0.4 minute 
Convert km/h to m/s:
(90 km/h)(1000m/1km)(1 h/3600s) = 25.000 m/s
(75 km/h)(1000m/1km)(1 h/3600s) = 20.833 m/s
Let time of catching up = t
The distance travelled by slower car = (20.833 m/s)(t)
The distance travelled by faster car = (25.000 m/s)(t)
The distance travelled by the faster car is 100 m longer than the slower car:
(20.833 m/s)(t)+100m = (25.000m/s)(t)
100 m = (25.000m/s  20.833 m/s)t
Without units:
100 = (25.000  20.833)t
You should ba able to find the time in seconds, t, on your own. 
The 100 m between the cars closes at a rate of 15km/h = 15,000 m/h
The gap becomes zero after 100/15,000 = 1/150 h = 0.40 min = 24 s
We all agree 
THANK YOU SOO MUCH!! THIS REALLY HELPED!!!
Respond to this Question
Similar Questions

bobprsly
I do apologize but I looked in the past post and i don't remember asking about this problem in math. But if i did then I do apologize but i don't remember what you said in as the responce. If you can copy and paste it for me to see. … 
english 2
Serious Story They were all slouching in their seats; making it obvious they didnâ€™t want to be there. One was holding on to practically cradling his blue bandana, another was looking at a bruise he had received during a fistfight … 
algebra
I asked this question earlier and wasn't sure what the answer was. Find all numbers for which the rational expression is undefined? 
Physics  Momentum of cars at intersection
Car A(1750kg) traveling due south and car B (1450kg)due east. They reach the same intersection at the same time and collide. The cars lock together and move off at 35.8km/h[E31.6degS]. What was the velocity of each car before the collided? 
AlgebrAlgebraMathmate or BobPursley or Reiny
I had asked a question earlier and bob pursley nicely answered it but I do have a question concerning it still perhaps someone could clarify it f(x) = logx is a logarthmic function. Bob Pursley said it could be because the base is … 
physics(please help...very urgent.....)
A ball is hit at an angle of 36 degrees to the horizontal from 14 feet above the ground. If it hits the ground 26 feet away (in horizontal distance), what was the initial velocity? 
physics
At car (1140kg)traveling at 76.04 m/s and truck (12600kg)traveling 6.88 m/s have a headon collision and then stick together. What is their final common velocity (m/s)? 
Math: Homework Questons (answer quick)
Can you check if the answer is correct and of there any grammar mistakes. Write True or False and EXPLAIN your reasoning for the answer!!!! 8. (5  2)  1 = 5  (2  1) Answer: True Reason: The reason why my answer to this question … 
Environmental Science
Can someone please help me with this question because when I post this question earlier, some lady or tutor just gave me some links on where to find the answer and I had already did that and still couldn't find an answer? 
Physics
I came here earlier with this question: "A force of 20 N acts toward the west. Another force acts at the same point so that the resultant of the two forces is zero. What is the magnitude and direction of the second force?