- #1
Jaimie
- 35
- 0
Hello, I hope someone can help me with this question.
"Design a simple experiment that you could carry out in your home to
i) determine the coefficient of static friction between an object and a surface.
ii) prove that the coefficient of static friction is dependent only on the surfaces in contact, and is not affected by any change in the mass of your object"
This is what I came up with.
1) Obtain and tape down with painter’s tape the architectural scale (ruler) so that the edge is 90degrees with the edge of the table top.
2) Obtain and tape protractor along the edge of the table so that the ‘x’ mark is aligned to the front edge of the scale and to the table top. Both taped scale and protractor will act as a jig to ensure there is little movement when raising the textured surfaces.
3) Place a piece of painter’s tape on the edge of the cutting board (closest to you) to mark the point at which the box will be placed at the start of each trail.
4) Place the wood cutting board flat on the table so that the front edge fits snuggly between the protractor and scale’s front edge. Align the full box of screws on the cutting board so the longest front edge is aligned with the tape marker.
5) Slowly raise the end of the cutting board surface just until the box just begins to slide downwards. Record the angle at which this occurs in the data table.
6) Repeat steps 4-5 two more times for a total of three trials and calculate the average angle value. (This angle will be used to calculate the static friction coefficient).
7) Calculate the static friction coefficient using the equation u= sin(theta) as derived from -Ff + Fgx = 0 for the surface and using the average angle value.
8) Repeat steps 4-7 with the box of screws 1/2 –full, then with the box empty. Record all values and calculations in the data table.
9) Obtain the plexiglass sheet clip it, with the binder clips, to on the board’s edge (closest to you). Repeat steps 4-8 and record all values and calculations in the data table.
10) Obtain the sheet of white paper and clip it (with the binder clips) to the cutting board. Repeat steps 4-8 and record all values and calculations in the data table.
Here are my results
Surface Average angle Static coefficient
Wood cutting board (w/Full box of screws)- 20.0 0.364
" (w/1/2 box of screws)- 20.8 0.380
" (empty) 22.8 0.420
Plexiglass (w/Full box of screws) 28.3 0.538
" (w/1/2 box of screws)- 34.0 0.674
" (empty box) 40.7 0.860
Paper (w/Full box of screws)- 20.0 0.364
" (w/1/2 box of screws)- 28.0 0.532
" (empty) 30.3 0.584
"Design a simple experiment that you could carry out in your home to
i) determine the coefficient of static friction between an object and a surface.
ii) prove that the coefficient of static friction is dependent only on the surfaces in contact, and is not affected by any change in the mass of your object"
This is what I came up with.
1) Obtain and tape down with painter’s tape the architectural scale (ruler) so that the edge is 90degrees with the edge of the table top.
2) Obtain and tape protractor along the edge of the table so that the ‘x’ mark is aligned to the front edge of the scale and to the table top. Both taped scale and protractor will act as a jig to ensure there is little movement when raising the textured surfaces.
3) Place a piece of painter’s tape on the edge of the cutting board (closest to you) to mark the point at which the box will be placed at the start of each trail.
4) Place the wood cutting board flat on the table so that the front edge fits snuggly between the protractor and scale’s front edge. Align the full box of screws on the cutting board so the longest front edge is aligned with the tape marker.
5) Slowly raise the end of the cutting board surface just until the box just begins to slide downwards. Record the angle at which this occurs in the data table.
6) Repeat steps 4-5 two more times for a total of three trials and calculate the average angle value. (This angle will be used to calculate the static friction coefficient).
7) Calculate the static friction coefficient using the equation u= sin(theta) as derived from -Ff + Fgx = 0 for the surface and using the average angle value.
8) Repeat steps 4-7 with the box of screws 1/2 –full, then with the box empty. Record all values and calculations in the data table.
9) Obtain the plexiglass sheet clip it, with the binder clips, to on the board’s edge (closest to you). Repeat steps 4-8 and record all values and calculations in the data table.
10) Obtain the sheet of white paper and clip it (with the binder clips) to the cutting board. Repeat steps 4-8 and record all values and calculations in the data table.
Here are my results
Surface Average angle Static coefficient
Wood cutting board (w/Full box of screws)- 20.0 0.364
" (w/1/2 box of screws)- 20.8 0.380
" (empty) 22.8 0.420
Plexiglass (w/Full box of screws) 28.3 0.538
" (w/1/2 box of screws)- 34.0 0.674
" (empty box) 40.7 0.860
Paper (w/Full box of screws)- 20.0 0.364
" (w/1/2 box of screws)- 28.0 0.532
" (empty) 30.3 0.584