Objective:
After completing this experiment, you should be able to measure the coefficient of sliding friction of an object that is located on an inclined plane.
Apparatus:
Inclined Plane
Pulley attachment for plane
Wooden blcok, with hook attached
Meterstick
Felt
Set of masses
String
Protractor
Procedure:
1. Place the board in the position shown in Figure 7-1.
2. The angle of the board should be small enough so that the wooden block will not slide down when it is placed on the board.
3. Increase the angle of the board gradually until the block slides down the board at constant velocity when it is given a slight push to start it.
4. Record this angle.
5. Also record the mass of the block as measured with a platform balance.
6. Repeat the above procedure, but place the block on its narrow side instead of its broad side.
7. Measure and record the angle as before.
8. For the third trial, cover the broad side of the block with sandpaper and measure the necessary angle.
9. For the remaining trials, attach a piece of string to the hook on the wooden block and pass the string over the pulley at the upper end of the inclined plane.
10. For trial 4, set the angle of the plane at 5 degree.
11. Attach enough masses to the free end of the string so that the block will slide with constant velocity up the plane when it is given a slight starting push.
12. For Trial 5, increase the angle by 10 degree and repeat the above procedure.
13. Repeat this process at 10 degree intervals until an angle of 55 degree has been reached.
14. Record all data.
Observation and Data:
Trial
Θ ( o )
Mass of block (kg)
1 (flat wood)
15 o
0.1431kg
2 (narrow wood)
14 o
0.1431kg
3 (Velcro)
20 o
0.1431kg
Trial
Θ ( o )
Mass added to string (kg)
4
5 o
0.05kg
5
15 o
0.09kg
6
25 o
0.1kg
7
35 o
0.11kg
8
45 o
0.13kg
9
55 o
0.15kg
FW
FP
FN
Ff
FH μ Trial
W
FG n f
T
μ
1
1.40 N
0.362 N
1.352 N
0.362 N
0.268
2
1.40 N
0.339 N
1.361 N
0.339 N
0.249
3
1.40 N