Wednesday, September 22, 2010

September 22

Hey
So today in class we did a lab showing the forces working on a block moving down an inclined plane. We needed to find the FORCE OF GRAVITY (Fw), FORCE OF PARALLEL (Fgx), FORCE OF PERPENDICULAR (Fgy), the ANGLE, and COEFFICIENT OF FRICTION (µ).

The Objective of the lab was to find the value of the coefficient of sliding function using an inclined plane



To learn the steps involved read page 19 in the Dynamics Unit

Questions

1.) Calculate Fgx, Fgy, and µ

Fgx = (sin24)(o.75N) [24 being the angle at which the block moved, and .75 being the force of the block]

Fgx = 0.31 N

Fgy = cos24(o.75N)

Fgy = 0.69N

The formula for finding µ is: µ = Fgx/Fgy

µ = 0.31N/0.69 N

µ = o.45

2.) Show that µ = tanθ
tan24 = 0.45



Next we read pages 172-179, and 194- 198, and doing questions 1-4 on pg 96 of the textbook

Questions

1.) A book leaves the printing press and slides down a 4.0m long ramp into the arms of a student. If the ramp is inclined at an angle of 25 degrees to the horizontal and has a coefficient of kinetic friction of 0.10, how long will it take the 2.0kg textbook to reach the student?

To be honest I don't know how to get the answer, so here's a basic diagram

For better information please as Ms. K.

1 comment:

Ms K said...

Thanks for posting. I made one change, coefficient of friction doesn't have any units. It is a ratio between frictional force and normal force.