Date: Wed, 18 May 2005 12:31:22 -0700

Author: "John Welch"

Subject: Re: Physics question

Post:

This is a multi-part message in MIME format.

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As Wolfgang said, you can get power from force and speed. Measuring speed w=
ould be the easy part. Measuring force would depend how much friction is in=
the belt. If there is a lot of friction, then most of the force you exert =
when you walk/run will be that required to overcome friction. If that frict=
ion were relatively independent of speed over the range of speeds involved,=
then you could treat that as a constant, and multiply speed times the forc=
e of friction. If there were very little friction (which is probably not th=
e case), you could attach a string and hanging weight to the treadmill in s=
uch a way that as you walk, you lift the weight. Then the power would be th=
e weight times the speed the mass rises. If the friction is intermediate be=
tween very large and very small, you could still raise a weight and call th=
at the "useful power output" and talk about efficiency.
If you had some kind of computer interface, like Vernier or Data Studio, yo=
u could measure velocity and have the program multiply by a force. If you w=
anted to do it more low tech, you'd have to come up with an elegant way to =
measure belt speed. I'm sure there are many good ways. A tiny little genera=
tor connected to the belt, or some kind of 'speedometer' from an industrial=
supply place. If a good idea pops into my head, I'll let you know. Good lu=
ck.
=20

----- Original Message -----=20
From: Larry Hess=20
To: tap-l@listproc.appstate.edu=20
Sent: Wednesday, May 18, 2005 4:52 AM
Subject: Re: Physics question

Thanks Dick,

It is actuaslly an old horse treadmill, that has no electrical power. It=
is the pushing of the feet that moves the tread., therefore there is no vo=
ltage or current.
The students, moving slow, walking fast, or running, on the treadmill ar=
e exerting energy. I was hoping somehow, to be able to convert this energy =
(or speed of motion) to horsepower. I know if the students run up a flight=
of stairs, mgh can be found, then converted to energy; but I am not clear =
how to get horsepower with the treadmill when the height is constant.=20

Maybe I have no horsesense here.

Larry=20
----- Original Message -----=20
From: Dick Heckathorn=20
To: tap-l@listproc.appstate.edu=20
Sent: Tuesday, May 17, 2005 9:57 PM
Subject: RE: Physics question

Greetings,

=20=20=20=20=20

I have a watt meter. If one plugs the power cord of the treadmill, the =
power would be given. But would this give what is wanted? If I had a treadm=
ill, I could plug it into the watt meter and see how it would vary with the=
speed.

=20=20=20=20=20

Wait a minute. Does the treadmill you are speaking of run by an electri=
c motor of just by the pushing of the feet. If by the pushing of the feet, =
neglect the above. Then again could one somehow attach a generator to the t=
readmill and measure the output wattage? Or the current and the voltage an=
d find P using P =3D I V.=20

=20=20=20=20=20

I'm not sure if this is even worth 2 cents. But.

=20=20=20=20=20

Dick

=20=20=20=20=20

=20=20=20=20=20

Helping teachers who facilitate, motivating students who learn.

Dick Heckathorn 14665 Pawnee Trail Middleburg Hts, OH 44130 440-826=
-0834

Physics Teacher CVCA 4687 Wyoga Lake Rd Cuyahoga Falls, OH 44224 330=
-929-0575 VM 120

www.cvcaroyals.org/~rheckathorn

Physics is learning how to communicate with ones environment so that is=
will talk back.

=20=20=20=20=20

-----Original Message-----
From: owner-tap-l@listproc.appstate.edu [mailto:owner-tap-l@listproc.ap=
pstate.edu] On Behalf Of Larry Hess
Sent: Tuesday, May 17, 2005 12:33 PM
To: tap-l@listproc.appstate.edu
Subject: Fw: Physics question

=20=20=20=20=20

=20=20=20=20=20

Can anyone help me with the following? Thanks in advance

=20=20=20=20=20

Here is what my Physics students would like to do.

=20=20=20=20=20

I have a small horse treadmill, and(somehow), we would like students to=
"run" on the treadmill, and in front of them have a large circular dial th=
at would indicate their horsepower. ie...faster they run, the more horsepo=
wer indicated. Each student's mass would be the same, "g" is constant, and=
their height above the ground would remain the same. Only the treadmill sp=
eed would change. How would we convert this to horsepower ?, and also, I a=
ssume we could .by belt, or cog gear, rig up a dial of some type; but calib=
rating it from speed of foot movement to conversion of horsepower is puzzl=
ing. Can this be done? Your thoughts would be greatly appreciated.

=20=20=20=20=20

Thanks,

=20=20=20=20=20

Larry Hess

Physics teacher

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As Wolfgang said, you can get power from f=
orce and=20
speed. Measuring speed would be the easy part. Measuring force would depend=
how=20
much friction is in the belt. If there is a lot of friction, then most of t=
he=20
force you exert when you walk/run will be that required to=20
overcome friction. If that friction were relatively independent of spe=
ed=20
over the range of speeds involved, then you could treat that as a constant,=
and=20
multiply speed times the force of friction. If there were very little frict=
ion=20
(which is probably not the case), you could attach a string and hanging wei=
ght=20
to the treadmill in such a way that as you walk, you lift the weight. Then =
the=20
power would be the weight times the speed the mass rises. If the frict=
ion=20
is intermediate between very large and very small, you could still raise a=
=20
weight and call that the "useful power output" and talk about=20
efficiency.

If you had some kind of computer interface=
,=20
like Vernier or Data Studio, you could measure velocity and have =
the=20
program multiply by a force. If you wanted to do it more low tech, you=
'd=20
have to come up with an elegant way to measure belt speed. I'm sure=20
there are many good ways. A tiny little generator conne=
cted=20
to the belt, or some kind of 'speedometer' from an industrial supply p=
lace.=20
If a good idea pops into my head, I'll let you know. Good=20
luck.

size=3D3>

----- Original Message -----

FT: #000000 2px solid; MARGIN-RIGHT: 0px">
style=3D"BACKGROUND: #e4e4e4; FONT: 10pt arial; font-color: black">Fro=
m:
=20
Larry Hess A>

Sent: Wednesday, May 18, 2005 4:52=
=20
AM

Subject: Re: Physics question

Thanks Dick,

It is actuaslly an old horse treadmill, =
that has=20
no electrical power.  It is the pushing of the feet that moves =
the=20
tread., therefore there is no voltage or current.

The students, moving slow, walking =
fast, or=20
running, on the treadmill  are exerting energy. I was hoping somehow=
, to=20
be able to convert this energy (or speed of motion) to horsepower.  =
I=20
know if the students run up a flight of stairs, mgh can be found, then=20
converted to energy; but I am not clear how to get horsepower with the=20
treadmill when the height is constant.

To: title=3Dtap-l@listproc.appstate.edu=20
href=3D"mailto:tap-l@listproc.appstate.edu">tap-l@listproc.appstate.edu=
=20

Sent: Tuesday, May 17, 2005 9:57=
=20
PM

Subject: RE: Physics question IV>

style=3D"FONT-SIZE: 10pt; COLOR: navy; FONT-FAMILY: Arial">Greetings, :p>

style=3D"FONT-SIZE: 10pt; COLOR: navy; FONT-FAMILY: Arial"> <=
/o:p>

style=3D"FONT-SIZE: 10pt; COLOR: navy; FONT-FAMILY: Arial">I have a wat=
t=20
meter. If one plugs the power cord of the treadmill, the power would be=
=20
given. But would this give what i
face=3DArial color=3Dnavy size=3D2> style=3D"FONT-SIZE: 10pt; COLOR: navy; FONT-FAMILY: Arial">s=20
w
2> style=3D"FONT-SIZE: 10pt; COLOR: navy; FONT-FAMILY: Arial">anted? If I =
treadmill, I could plug it into the watt meter and see how it would var=
y=20
with the speed.

style=3D"FONT-SIZE: 10pt; COLOR: navy; FONT-FAMILY: Arial"> <=
/o:p>

style=3D"FONT-SIZE: 10pt; COLOR: navy; FONT-FAMILY: Arial">Wait a minut=
e. Does=20
the treadmill you are speaking of run by an electric motor of just by t=
he=20
pushing of the feet. If by the pushing of the feet, neglect the above. =
Then=20
again could one somehow attach a generator to the treadmill and measure=
the=20
output wattage?  Or the c=
urrent=20
and the voltage and find P using P =3D I V.
P>

style=3D"FONT-SIZE: 10pt; COLOR: navy; FONT-FAMILY: Arial"> <=
/o:p>

style=3D"FONT-SIZE: 10pt; COLOR: navy; FONT-FAMILY: Arial">I=92m not su=
re if=20
this is even worth 2 cents. class=3DGramE>But=85

style=3D"FONT-SIZE: 10pt; COLOR: navy; FONT-FAMILY: Arial"> <=
/o:p>

style=3D"FONT-SIZE: 10pt; COLOR: navy; FONT-FAMILY: Arial">Dick :p>

style=3D"FONT-SIZE: 10pt; COLOR: navy; FONT-FAMILY: Arial"> <=
/o:p>

style=3D"FONT-SIZE: 10pt; COLOR: navy; FONT-FAMILY: Arial; mso-no-proof=
: yes">

style=3D"mso-bidi-font-weight: normal"> olor=3Dnavy=20
size=3D1> style=3D"FONT-WEIGHT: bold; FONT-SIZE: 7.5pt; COLOR: navy; mso-no-proof=
: yes; mso-bidi-font-weight: normal">Helping=20
teacher
style=3D"mso-bidi-font-weight: normal"> N=20
style=3D"FONT-WEIGHT: bold; FONT-SIZE: 7.5pt; COLOR: navy; mso-no-proof=
: yes; mso-bidi-font-weight: normal">s=20
w
style=3D"mso-bidi-font-weight: normal"> N=20
style=3D"FONT-WEIGHT: bold; FONT-SIZE: 7.5pt; COLOR: navy; mso-no-proof=
: yes; mso-bidi-font-weight: normal">ho=20
facilitate, motivating student
style=3D"mso-bidi-font-weight: normal"> N=20
style=3D"FONT-WEIGHT: bold; FONT-SIZE: 7.5pt; COLOR: navy; mso-no-proof=
: yes; mso-bidi-font-weight: normal">s=20
w
style=3D"mso-bidi-font-weight: normal"> N=20
style=3D"FONT-WEIGHT: bold; FONT-SIZE: 7.5pt; COLOR: navy; mso-no-proof=
: yes; mso-bidi-font-weight: normal">ho=20
learn.

align=3Dcenter> avy=20
size=3D1> s">Dick=20
Heckathorn
PAN=20
style=3D"FONT-SIZE: 7.5pt; COLOR: navy; mso-no-proof: yes"> style=3D"mso-spacerun: yes">  14665 Pawnee Trail style=3D"mso-spacerun: yes">  Middleburg Hts, OH style=3D"mso-spacerun: yes">  44130 style=3D"mso-spacerun: yes"> =20
440-826-0834

=20
face=3D"Times New Roman" color=3Dnavy size=3D1> style=3D"FONT-SIZE: 8pt; COLOR: navy; mso-no-proof: yes">Physics Teache=
r=20
CVCA  4687 Wyoga Lake Rd<=
SPAN=20
style=3D"mso-spacerun: yes">  Cuyahoga Falls, OH 44224 =20
style=3D"mso-spacerun: yes">  330-929-0575 style=3D"mso-spacerun: yes">  VM 120 T>

=20
face=3D"Times New Roman" color=3Dnavy size=3D1> style=3D"FONT-SIZE: 8pt; COLOR: navy; mso-no-proof: yes">www.cvcaroyals=
.org/~rheckathorn

=20
face=3D"Times New Roman" color=3Dnavy size=3D1> style=3D"FONT-SIZE: 8pt; COLOR: navy; mso-no-proof: yes">Physics is lea=
rning=20
how to communicate with ones environment so that=20
i style=3D"FONT-SIZE: 8pt; COLOR: navy; mso-no-proof: yes">s=20
w
style=3D"FONT-SIZE: 8pt; COLOR: navy; mso-no-proof: yes">ill talk=20
back.

style=3D"FONT-SIZE: 10pt; COLOR: navy; FONT-FAMILY: Arial"> <=
/o:p>

ize=3D2> style=3D"FONT-SIZE: 10pt; FONT-FAMILY: Tahoma">-----Original=20
Message-----
From:=
=20
owner-tap-l@listproc.appstate.edu [mailto:owner-tap-l@listproc.appstate=
.edu]=20
On Behalf Of Larry=20
Hess
Sent: Tuesday, =
May 17,=20
2005 12:33 PM
To:=20
tap-l@listproc.appstate.edu
style=3D"FONT-WEIGHT: bold">Subject: Fw: Physics=20
question

ew Roman"=20
size=3D3>  >

ew Roman"=20
size=3D3> style=3D"FONT-SIZE: 12pt">

ze=3D2> style=3D"FONT-SIZE: 10pt; FONT-FAMILY: Arial">Can anyone help me with t=
he=20
following?    Thanks in=20

ew Roman"=20
size=3D3> style=3D"FONT-SIZE: 12pt">

ze=3D2> style=3D"FONT-SIZE: 10pt; FONT-FAMILY: Arial">Here is what my Physics s=
tudents=20
would like to do.

ew Roman"=20
size=3D3> style=3D"FONT-SIZE: 12pt">

ze=3D2> style=3D"FONT-SIZE: 10pt; FONT-FAMILY: Arial">I have a small horse trea=
dmill,=20
and(somehow), we would like students to "run" on the treadmill, and in =
front=20
of them have a large circular dial that would indicate their=20
horsepower.  ie...faster they run, the more horsepower indicated.&=
nbsp;=20
Each student's mass would be the same, "g" is constant, and their heigh=
t=20
above the ground would remain the same. Only the treadmill speed w=
ould=20
change.  How would we convert this to horsepower ?, and also, I as=
sume=20
we could .by belt, or cog gear, rig up a dial of some type; but calibra=
ting=20
it from speed of foot movement  to conversion of horsepower i=
s=20
puzzling.  Can this be done?  Your thoughts would be greatly=
=20
appreciated.

ew Roman"=20
size=3D3> style=3D"FONT-SIZE: 12pt">

ze=3D2> style=3D"FONT-SIZE: 10pt; FONT-FAMILY: Arial">Thanks, >

ew Roman"=20
size=3D3> style=3D"FONT-SIZE: 12pt">

ze=3D2> style=3D"FONT-SIZE: 10pt; FONT-FAMILY: Arial">Larry=20
Hess

ze=3D2> style=3D"FONT-SIZE: 10pt; FONT-FAMILY: Arial">Physics=20
teacher

TE>

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From mburns-k@spelman.edu Wed May 18 15:32:43 2005

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