plane trigonometry

Submitted by juliepearl on

a weight of 350 pounds is being pulled up an incline at at a uniform speed.the incline makes an angle of 18 degree 25 minutes with the horizontal.the force pulling thye weight makes an angle of 27 degree 20 minutes with the incline.if the coefficient of sliding friction is 0.42, find the magnitude of the force.

Jhun Vert Sat, 03/14/2015 - 12:04

This is more of engineering mechanics than trigo. Anyway here it is:
 

win_20150314_114841.jpg

 

θ = 18° 25'
Φ = arctan (0.42) = 22.78°

Draw the force polygon:
 

win_20150314_114744.jpg

 

α = 18° 25' + 27° 20'

Solve for β then use sine law to solve for P.

My answer is 231.26 lbs.