Friction Lab

In this lab we were trying to find the coefficient of friction. We had a block of wood and we lifted it up until it slide down, then we use a protractor and measured the angle of the piece of wood. After finding the vectors we found of resolved them into components and and used sin, cos, and tan to find the rest of the measurements.

Hooke's Law

OSCILLATIONS

Materials:
metal rod
clamp
spring
rubberband
weights
timer
videor
calculations

Procedure:

the first thing we measured was the length of the spring without any weight on it. then we added weight and slightly pulled the spring to a certain distance and counted how many oscillations were in a certain amount of time. we choose to time all the oscillations for ten seconds and count the number there were in that time period. once we did multiple weights we calculated the displacement vs force and the period vs force.

Results:
the more weight that you put on the spring, the slower the oscillations became.












video

Inertia Trick

Video
  
Inertia is the property of matter by which it retains its state of rest or its velocity along a straight line so long as it is not acted upon by an external force.

In our trick we stacked several nickels on top of each other and we were told to use a knife or a thin, flat object to see if we could move the bottom nickel without moving the others. The first couple of tries we failed to do so, but after many tries we finally accomplished our goal of doing it correctly. This inertia trick shocked us, even though it was simple on the outside it was a very intense task to complete.

Chair Activity

I learned that you use more force when something or someone is in the chair, than when the chair is empty.

We placed a person in a rolling chair and pushed them down the hall. Then we pushed the rolling chair empty, and after that we put a forty five pound weight in the rolling chair while someone was in it.

 It took more force to push the chair with someone in it and gave it a big acceleration, and less force when the chair was empty and gave it a little acceleration.

2d motion analysis

video

Work for problem:

a = 9.8m/s^2
Change in vertical direction = .87m
t = ?

delta y = t + 1/2(a)^2(t)^2
.87m = 1/2 (9.8)^2(t)^2
.87m = 4.9(t)^2
.174 = t^2
.42s=t

We repeatedly calculated the measurements for the precise length from the table to the ground. When we measured the height of the table it came out that when we rolled the ball it hit the ruler. When could use this to balance the wings on an airplane.

bug lab

Procedure
     1. Set up a box for the bug with a grid in the bottom.
     2. Record the bug in the box for about 30 to 45 seconds.
     3. Watch the video and -pick out an interesting section about 10 seconds long.
     4. Get the bugs position and watch the video frame by frame stopping occasionally to write down the frame number and bugs position.
     5. Finally put all of the data in a spreadsheet.

 Analysis: https://docs.google.com/spreadsheet/ccc?pli=1&hl=en_US&key=0At_vITP2336KdDdrQ3ZfcDA0VW5Dbk1PRjJEd21PdFE#gid=0

Graph: https://docs.google.com/spreadsheet/ccc?pli=1&hl=en_US&key=0At_vITP2336KdDdrQ3ZfcDA0VW5Dbk1PRjJEd21PdFE#gid=0

Conclusions: I learned that distance and displacement are two totally different things. I found that this principal can be applied in driving. If you leave a parking lot and come back to the same parking spot your displacement is 0 but your distance isn't.