# Simple Tension Problem

A block with mass M = 5kg sits at rest on a frictionless incline. The mass is connected to the wall by a string with linear density μ = 5.0 g/m. The incline is fristionless, with angle Θ = 30°. Let the positive x-direction point up along the incline, and let the origin (x=0) be at the end of the string attached to the mass. HERE IS A DIAGRAM OF WHAT THE PROBLEM LOOKS LIKE: http://ift.tt/1fe656B

Draw a free body diagram of the block. What is the normal force on the block?

**2. Relevant equations**

This is probably where I’m lacking. I’m not sure if there is an equation that will give me a way of solving for T or not, but other than that there are no real equations necessary.

**3. The attempt at a solution**

I’m having no real problems with the free body diagram. It’s simple enough. The issue I’m having is that I don’t know how to calculate the Normal force on the block due to the incline. I calculate that:

N[itex]\ast[/itex]sin(60) + T[itex]\ast[/itex]sin(30) = mg

N = [itex]\frac{(mg – 1/2T)}{sin(60)}[/itex]

N = [itex]\frac{(2mg – T)}{\sqrt{3}}[/itex]

But now the only way I can see myself solving for N is with the value of T, which I can’t seem to figure out. Am I just missing a valuable equation?

http://ift.tt/1fe62YF

## Leave a comment