# Torque on Wrench

1. Nov 12, 2008

### lacar213

1. The problem statement, all variables and given/known data
You want to exert a torque of at least 35.0 N·m on a wrench whose handle is 0.150 m long. If you can provide a force of 355 N to the end of the wrench, what is the minimum angle at which you can apply the force in order to achieve the desired torque?

2. Relevant equations
t = rfsinθ

3. The attempt at a solution
I am not sure how to rearrange this equation to find the angle or what other equation I have to use to find the angle.
torque = 35.0 NM
F = 355 N
M = .150 M

2. Nov 12, 2008

### asleight

$$\vec{\tau}=\vec{r}\times\vec{F}\rightarrow\frac{\vec{\tau}}{rF}=\sin(\theta)$$...

3. Nov 12, 2008

### lacar213

After you divide the torque by the length and force do you take the sin of that answer - because when you do it is very small??

4. Nov 12, 2008

### asleight

You apply the arcsin function to both sides of the equation, yielding:

$$\arcsin\left(\frac{\vec{\tau}}{rF}\right)=\theta$$.