PhysicsLAB

Lab
Coefficient of Friction Results
Enter each group member's AIDE letters
Lab Station #
Select period

 

For the situation illustrated above,
where the plate has both 500 gram masses on top of it,
check off which force(s) would belong on a freebody diagram of the plate

F
G
H
I.gif (947 bytes) I
J.gif (976 bytes) J
A

B

C

D

E

Data Table

 mass
in grams		 mass
in kg		 spring scale
reading
in newtons		 normal
in newtons		 coefficient of friction
mk
spring scale/normal		 percent difference
steel plate

steel plate with 500 gram added
steel plate with 1000 grams added

average

Why should the coefficient of friction have been the same in all three trials?

 

 


Part II. Static Friction
Slowly tilt the incline until the mass JUST starts to slide. 
Record the incline's angle of elevation in Data Table II.

frictionincline.gif (2660 bytes)

For the situation illustrated above,
where the wooden block has one 200 gram mass on top of it,
check off which force(s) would belong on a freebody diagram of the block

    F.gif (961 bytes) F
G
H
A

B

C

D

E

Data Table II

 mass
in grams		 mass
in kg		 angle
of
repose		 component of
weight
acting parallel
to the incline
Fd = mg sin q
in newtons		 normal
Fn = mg cos q
in newtons		 coefficient of friction
ms = Fd / Fn
wooden block

wooden black with
200 grams added
wooden block with
400 grams added

averages

Once the block starts slipping, would the angle determined in this experiment be greater than, equal to, or less than the angle that would allow the block to slide down the remainder of the incline at a constant velocity? Explain.