Trig :/

[ballin1225]

Two cars make an 8-mile trip. One car has 13-inch-radius tires and the other car has 15-inch-radius tires. Find the number of revolutions (correct to the nearest hundred) each tire makes.

 

[Deleted member 4993]

Two cars make an 8-mile trip. One car has 13-inch-radius tires and the other car has 15-inch-radius tires. Find the number of revolutions (correct to the nearest hundred) each tire makes.

How much does The center of the circular wheel move horizontally - when it rolls once without slipping on a horizontal plane? = the circumference of the wheel

What does that tell you?

How can you use that fact in solving the problem?

Please show us your work, indicating exactly where you are stuck - so that we know where to begin to help you.

 

[ballin1225]

i'm just really not sure how to start the problem.

 

[Deleted member 4993]

i'm just really not sure how to start the problem.

I am trying to help you to do just that....

Think

and answer my questions.

 

[ballin1225]

well the circumference of the circle is 360 degrees right?

 

[Denis]

Hmmm....better go do some reading:

http://www.google.ca/search?hl=en&sourc ... =&aq=f&oq=

 

[Deleted member 4993]

well the circumference of the circle is 360 degrees right?

Circumference of a circle - is same as perimeter - it is a "distance". It cannot be a measure of an angle (360°).

By the way, the problem you posted is not a trig problem.

 

[ballin1225]

ok well my trig teacher gave it to us so i just posted it as trig.

 

[ballin1225]

does this sound right?-

1. 8 * 5,250= 42,240 feet
2. 42,240 * 12= 506,880 inches
3. 506,880/ (13* 3.14)=12414
4. 506,880/ (15* 3.14) =10762

 

[Deleted member 4993]

does this sound right?-

1. 8 * 5,250= 42,240 feet
2. 42,240 * 12= 506,880 inches
3. 506,880/ (13* 3.14)=12414
4. 506,880/ (15* 3.14) =10762

Almost correct - the circumference is 2*pi*r - you have used pi*r

Remember the answers need to be in nearest hundreds.