The question is:
How long would it take a car to return to its starting place if it traveled 180km at an average speed of 90km/hr and returned to its starting place along the same straightline path? (Neglect the time that the car takes to turn around.)
How do I work this problem out? Do I use the a^2 +b^2 = c^2? If so how do I use that? Thanks a lot.
2007-04-14 11:57:57 · 6 answers · asked by Anonymous in Education & Reference ➔ Homework Help
If you average speed is 90k/hr then it would take you two hours to drive 180 km.
180/90 = 2
and then the same back
180/90 = 2
It would take the car 2 hours to travel back if they maintain the same average speed as when they went.
2007-04-14 12:09:33 · answer #1 · answered by Anonymous · 0⤊ 0⤋
There are two possible answers to this question!
If the car traveled a total of 180km it would be the distance traveled divided by the average speed. This would give the time taken.
If the car traveled 180kms there and the same distance back it would be 180kms times two divided by the average speed. Again the answer would be the time taken.
The formula you gave seems to complicate things.
You will find with physic and chemistry if you lay out the information that you know and the information that you need. You will be able to work out the formula needed. Usually the simplest formula will give you the answer.
2007-04-14 19:17:05 · answer #2 · answered by peter w 4 · 0⤊ 0⤋
No, you do not need the Pythagorean Theorem. This is Algebra, not Geometry.
That said, let x stand for the number of hours. To find out how many hours it would take for the car to go out 180 km and return along a straight line, multiply 180 by 2 (360).
You know that the car is going 90 km/hr and it has traveled 360 km. Now it is time to solve for x.
90x = 360
To solve for x, you have to get it standing alone. To get it standing alone, you need to do the inverse operation of multiplying (90x is the same as saying 90 times x). The inverse operation is division.
90x/90 = 360/90
x = 4
2007-04-14 19:36:56 · answer #3 · answered by PuttPutt 6 · 0⤊ 0⤋
4 hours
2007-04-14 22:41:06 · answer #4 · answered by Anonymous · 0⤊ 0⤋
you do not use that formula. the formula is for finding the lengths in a right triangle
the amount of time is 2 hoursto return
2007-04-14 19:09:24 · answer #5 · answered by publius 2 · 0⤊ 0⤋
90km is half of 180...
One hour of travel will take you 90 km...
I assume you can perform basic mathematics...
2007-04-14 19:07:33 · answer #6 · answered by jcurrieii 7 · 0⤊ 1⤋