One last question:
If a 12lb. block is slowly tilted from horizontal when the plank reaches 30 degrees the block begins to slide.
To find the coefficient of the static friction you take the tangent form of 30 degrees?
To find the friction force you multiply the coefficient of the static friction times the weight?
But how do you find the Fn?
2 answers
This looks like a more carefully worded version of a questiona already answered
See the answer to http://www.jiskha.com/display.cgi?id=1201404660
1 answer