in a demonstration designed to determine the coefficient of friction for a book on a wooden plank, one end of the plank was raised until the book on it began to slide. if sliding commenced when the plank was at an agle of 37 degrees above the horizontal, what was the coefficient of static friction?
Friction = constant * F
Fmg = Mass * 9.8
The Attempt at a Solution
where in the world do I start with his. I have no mass so I can't find mg. I have nothing to start from but the 37 degrees. I can't even try trigonometry becoz I have no other values. I know that the friction constant changes depending on the surfaces and this is a wooden one - am I supposed to memorize all the constants?
I have no idea
Can anybody shed some light on this - I have an exam tomorrow.