Date: Wed, 12 Oct 2011 21:36:16

Author: Sam Sampere

Subject: another Vernier question

Post:

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Ok, I've noticed this in the past, but now it's really bugging me because I=
'm teaching the class.

If you've ever done N3 using 2 force probes, you'll notice that the curves =
are a tiny bit displaced from one another. I've attributed this to the timi=
ng differences, collect FP1, then FP2, then FP1, etc.

Now I'm doing an impulse-momentum demo - crash a car into a piece of rubber=
. Plot the F-t curve and the v-t curve.

I've set LP to collect 1000 pts/s. I know, the MD cannot do that, so LP set=
s that to 20 pts/s.

I start to see the change in v maybe 10 or 15 points BEFORE there is anythi=
ng on the FP. Why???

Barring that, it's a beautiful experiment. Integrate F-t, measure delta v, =
and you get quite good agreement. I'm using LP3.8.4 if that's of any issue =
with a Vernier MD and a wireless FP.

Thanks!

Sam


--------------------------
Sam Sampere
Syracuse University
Department of Physics
201 Physics Building
Syracuse, NY 13244
315-443-5999
315-443-9103 (fax)

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Ok, Iíve n=
oticed this in the past, but now itís really bugging me because IR=
17;m teaching the class. If youíve ever done N3 using 2 force probe=
s, youíll notice that the curves are a tiny bit displaced from one an=
other. Iíve attributed this to the timing differences, collect FP1, t=
hen FP2, then FP1, etc. Now Iím doing an impulse-momentum demo =
211; crash a car into a piece of rubber. Plot the F-t curve and the v-t cur=
ve. Iíve set LP to collect 1000 pts/s. I know, the MD cannot do tha=
t, so LP sets that to 20 pts/s.&nb=
sp;I start to see the change in v maybe 10 o=
r 15 points BEFORE there is anything on the FP. Why??? Barring that, it&#=
8217;s a beautiful experiment. Integrate F-t, measure delta v, and you get =
quite good agreement. Iím using LP3.8.4 if thatís of any issue =
with a Vernier MD and a wireless FP. Thanks! Sam -------------------------- Sam Sampere <=
br>Syracuse University Department of Physics 2=
01 Physics Building Syracuse, NY 13244 315-443-5999=
315-443-9103 (fax) =

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