# Homework Help: Force components question

1. Jan 15, 2008

### david18

1. The problem statement, all variables and given/known data
I need to find the component of W (the 400N force) that is parallel to the slide as in the attached picture. As you can see there is a 24 degree angle between the surface and ground.

2. Relevant equations

3. The attempt at a solution

I should be using simple trigonometry. The equation I am looking for is 400cos66 (or the appropriate version of sin) to give me an answer of 163N. So any help on how to find the triangle that would help me solve this problem would be appreciated.

#### Attached Files:

• ###### physics - forces.PNG
File size:
843 bytes
Views:
121
2. Jan 15, 2008

### Staff: Mentor

Seems that you already know that the parallel component is $W\cos66$ (which is the same as $W\sin24$). So what do you need a triangle for?

Check this out: http://www.glenbrook.k12.il.us/gbssci/Phys/Class/vectors/u3l3e.html" [Broken]

Last edited by a moderator: May 3, 2017
3. Jan 15, 2008

### blochwave

I think he knows it but doesn't know why

You have that 400 N force going down, break it into the two components, one is the component parallel to the incline, one is the component perpendicular to the incline(going down and to the right, of course)

Do you remember how to add vectors pictorally? Like so