Need help with statics problem

[bobbarkernar]

Homework Statement

a 2.9 lb force P is appplied to the lever which controls the auger of a snowblower. determine the value of alpha knowing that the moment of P about A is counterclockwise and has a magnitude of 17 lb*in

Homework Equations

The Attempt at a Solution

i thought i could do it using moment= F*d
so 17=2.9 tan^-1(alpha)*4.8 see picture attatched
i did it this way and i was a couple of decimas off so if someone can point me in the right direction thank you

 

[teknodude]

M = F*d only applies if your moment arm is perpendicular to the line of action of the force.

This is a 2-D problem so you have 3 equations that you can write down. Once that's done, you can see how to solve for the angle.

 

[piercas]

I would suggest checking your calculations and making sure you are using the correct units for each variable. It is also important to consider the direction of the moment and whether it is positive or negative. You may also want to try using the formula for moment in terms of force and distance from the pivot point, M = F*d*sin(alpha), and solving for alpha. If you are still having trouble, it may be helpful to seek assistance from a tutor or your instructor.