TRIG FUNCTION AGAIN

S

ShannonR.

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Feb 7, 2010
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Ben is pulling on a tobaggan rope with a force of 250 newtons. The rope makes a 36 degree angle with the ground. What force is actually working to move the toboggan to the right?

I don't even know where to go with this or how to start it.

----AND---

If a boat is going 6 mi/hr in still water suddenly encounters a crosscurent of 4 mi/hr, at what angle will the boat ver.

Again, I don't know where to start or how either of these deal with SOH-CAH-TOA and right triangles?
Please help me someonee. :(
 
Yes, right-angle trigonometry is used, to answer these questions.

Do you understand vectors?

We could start by drawing a picture.

Code: 
              /^
     250    /  |
          /    |
        /      |
      /        |
    /          |
  /  36°       |
/______________>

The diagonal vector represents the force of 250. It is the vector sum of two other forces: horizontal force + vertical force.

These two component forces are the legs of that right triangle. They want the magnitude of the horizontal force (i.e., the length of the horizontal vector).

Draw a picture of the boat vector (vertical), the cross-current vector (horizontal), and then add them to get the resulting vector (hypotenuse).

Cheers ~ Mark
 
Alright is there anyone else whilling to help me out? That made no sensee; Thank you thoughh Mark?
 
Okay, let's forget the physics aspect of this exercise, for now.

Do you know how to find the length of the base of the right triangle, in my diagram above?
 
All I know is we need to use either Cosine, Tangent, or Sine on our calculators based on SOH-CAH-TOA.
But I have no idea which side is opposite,adjacent, or the hypotense and I have no idea which one to use of SOH, CAH, or TOA.
 
Sorry for the delay; I think my ISP is overloaded secondary to Super Bowl activity.

You really need to learn the basic definitions of a right triangle and its parts, before studying trigonometry.

In a right triangle, the longest side is called the hypotenuse. Since the 90-degree angle is always the largest angle inside a right triangle, the hypotenuse is always opposite the 90-degree angle.

In my diagram, the length of the hypotenuse is labeled: 250.

The angle that the rope makes with the ground is 36 degrees, as labeled.

The base of the triangle is the "adjacent side" of the angle, and the vertical side of the right triangle is the side "opposite" the 36 degree angle.

You want to find the length of the base, in other words, the length of the adjacent side. So, the cosine ratio is used because it does not require knowing the length of the opposite side.

You know the angle measurement, and you know the hypotenuse. Substitute them into the definition of the cosine ratio.

cos(36 degrees) = Adjacent/250

Solve this for Adjacent.
 
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