Part A: Coefficient of static friction 1. Place the penny (head up) at one end o
ID: 1527656 • Letter: P
Question
Part A: Coefficient of static friction
1. Place the penny (head up) at one end of the textbook cover, and lift the textbook very slowly, until the coin just begins to slip down the incline.
2. Measure the angle of incline with the protractor.
3. Repeat the measurement 5 times, and find the average of this critical angle c.
Draw on the figure the forces acting on the coin.
Trial 1
Trial 2
Trial 3
Trial 4
Trail 5
Average
c
20 deg.
23 deg.
24 deg.
20 deg.
21 deg.
21.6 deg.
4. Calculate now the coefficient of static friction between the coin and the material:
s = tan c =
5. Calculate now the coefficient of kinetic friction between the coin and the material:
k = tan 'c =
Trial 1
Trial 2
Trial 3
Trial 4
Trail 5
Average
c
20 deg.
23 deg.
24 deg.
20 deg.
21 deg.
21.6 deg.
Explanation / Answer
here only we can calculate the static friction from the data of the table
now the coefficient of static friction between the coin and the material:
s = tan c = tan 21.6 = 0.396