I placed a board eraser on the flatwood board. I Slowly lift one end of the board and continued increasing the angle of the board with the horizontal until the object starts to slide. Use the protractor to measure this angle. I Record the valued of this angle in Table 3 as the ^q&angle for static friction. The tangent of this angle is the coefficient of static friction.

i recorded the results on the table below:

	Description
Object	Board Eraser
Surface	Flat wood

Table 2

Weight of object (N)	0.3N	0.3N	0.3N	0.3N
Force of sliding friction (N)	1	2	3	Average
	0.2N	0.2	0.2N	0.2N

Table 3

Motion	Angle (degrees)	p = tan 9
Static	25	0.55s
Sliding	45	0.27k

1. calculate the coefficients of static and sliding friction for the object used.

2.Explain any difference between the values for the coefficients of static and sliding friction

3. calculate coefficient for sliding friction using data from the table.

4.Are your values for Psiiding from Questions 1 and 3 equal? Explain any differences

5.A brick is positioned first with its largest surface in contact with an inclined plane. The plane is tilted at an angle to the horizontal until the brick just begins to slide, and the angle, 9, of the plane with the horizontal is measured. Then the brick is turned on one of its narrow edges, the plane is tilted, and is measured. Predict whether there will be a difference in these measured angles. Explain your answer in terms of the equation for the force of friction. Is the coefficient of static friction affected by the area of contact between the surfaces?

6.A brick is placed on an inclined plane, which is tilted at an angle to the horizontal until the brick just begins to slide. The angle, 6, of the plane with respect to the horizontal is measured.