Data table – PASCO ME-9502 Statics System User Manual
Page 46
S t a t i c s S y s t e m
E x p . 8 : S l i d i n g F r i c t i o n
®
42
012-12876B
•
If the Friction Block stops, the mass is too light. If the Friction Block accelerates, the mass is too heavy.
•
The weight of the hanging mass that is sufficient to pull the Friction Block at a constant speed is f
k
, the force
of the sliding (kinetic) friction between the Friction Block and the Inclined Plane.
Variables
Change the following factors and measure the sliding friction force.
•
Normal Force: Add mass to the top of the Friction Block to increase the normal force between the block and
the Inclined Plane.
•
Contact Material: Two sides of the Friction Block are bare wood. Two other sides are covered with felt.
Compare the sliding friction force for a wood surface to the sliding friction force for an equally sized felt sur-
face.
•
Contact Area: The top and bottom surfaces have a larger area than the side surfaces. Compare the sliding
friction force for a larger area to the sliding friction force for a smaller area.
Reminders for each trial:
•
Carefully adjust the mass on the mass hanger until the weight of the hanging mass is enough so that the Fric-
tion Block moves at a very slow, constant speed after you give it a small push.
•
Record the total mass of the Friction Block, M, and the hanging mass, m, (total mass of the mass hanger and
added masses).
•
Calculate and record the normal force, F
N
, of the Friction Block on the Inclined Plane and the sliding friction
force, f
k
(weight of the hanging mass).
•
Calculate and record the coefficient of friction,
, which is the ratio of the sliding friction force, f
k
, divided by
the normal force, F
N
Data Table
*For trials 7 through 10, let the total mass of the Friction Block be constant.
Trial
Added Mass
(kg)
Total Mass,
M, of Block
Normal Force,
F
N
= Mg
Hanging
Mass, m
Friction
force, f
k
= mg
Coefficient of
friction,
= f
k
/F
N
1
0.000
2
0.050
3
0.100
4
0.150
5
0.200
6
0.250
Trial
Surface
Total Mass,
M, of Block*
Normal Force,
F
N
= Mg
Hanging
Mass, m
Friction
force, f
k
= mg
Coefficient of
friction,
k
= f
k
/F
N
7
Wood, Large
8
Felt, Large
9
Wood, Small
10
Felt, Small