Dumb Undergraduate question



 Science > Physics > Dumb Undergraduate question

LINK TO THIS PAGE  


rating :  0   |  0


  Page 1 of 1

1

 
Topic: Science > Physics
User: "Timtro"
Date: 20 Nov 2003 04:09:21 AM
Object: Dumb Undergraduate question
Hi. I found a question in my first year text book that I can't answer. I'm
sorry to bother you all, but I am simply too embarassed to ask my prof. I
really should know this by now
If I were to put a pendulum in a accelerating truck, how would it affect the
period?
The question also asks about a pandulum in an accelerating elivator, but I
assumed that you simply add the acceleration due to gravity to the elevators
acceleration vector and use that instead of g in the equation for period
(T=2Pi*sqrt(r/g)).
.

User: "Greg Neill"

Title: Re: Dumb Undergraduate question 20 Nov 2003 08:43:59 AM
"Timtro" <timtro@rogers.com> wrote in message
news:lp0vb.67746$j1d.5148@news04.bloor.is.net.cable.rogers.com...

Hi. I found a question in my first year text book that I can't answer. I'm
sorry to bother you all, but I am simply too embarassed to ask my prof. I
really should know this by now

If I were to put a pendulum in a accelerating truck, how would it affect

the

period?

The question also asks about a pandulum in an accelerating elivator, but I
assumed that you simply add the acceleration due to gravity to the

elevators

acceleration vector and use that instead of g in the equation for period
(T=2Pi*sqrt(r/g)).

Your answer to this second part should give you a big
clue to the first part. Think "vector addition".
.
User: "Timtro"

Title: Re: Dumb Undergraduate question 20 Nov 2003 09:01:52 AM
"Greg Neill" <gneillREM@OVE.netcom.ca> wrote in message
news:Cq4vb.7522$Mu.70348@weber.videotron.net...

"Timtro" <timtro@rogers.com> wrote in message
news:lp0vb.67746$j1d.5148@news04.bloor.is.net.cable.rogers.com...

Hi. I found a question in my first year text book that I can't answer.

I'm

sorry to bother you all, but I am simply too embarassed to ask my prof.

I

really should know this by now

If I were to put a pendulum in a accelerating truck, how would it affect

the

period?

The question also asks about a pandulum in an accelerating elivator, but

I

assumed that you simply add the acceleration due to gravity to the

elevators

acceleration vector and use that instead of g in the equation for period
(T=2Pi*sqrt(r/g)).


Your answer to this second part should give you a big
clue to the first part. Think "vector addition".

That is where my problem is. For the second part, the vectors were vertical
because the period in this case depends on only the vertical component of
acceleration (based on the derivation, it is (Rsin(theta)/gsin(theta) = R/g)
Thats why I am so embarassed. I don't know how to handel this problem. I
know there was a time when this would have been no question to me :) Its
been so long since i even though about this.
.


User: "Paul Cardinale"

Title: Re: Dumb Undergraduate question 20 Nov 2003 09:08:25 AM
"Timtro" <timtro@rogers.com> wrote in message news:<lp0vb.67746$j1d.5148@news04.bloor.is.net.cable.rogers.com>...

Hi. I found a question in my first year text book that I can't answer. I'm
sorry to bother you all, but I am simply too embarassed to ask my prof. I
really should know this by now

If I were to put a pendulum in a accelerating truck, how would it affect the
period?

The question also asks about a pandulum in an accelerating elivator, but I
assumed that you simply add the acceleration due to gravity to the elevators
acceleration vector and use that instead of g in the equation for period
(T=2Pi*sqrt(r/g)).

Do the truck problem the same as the elevator problem, remembering
that acceleration is a vector (you can do vector addition, right?).
Paul Cardinale
.

User: "Randy Poe"

Title: Re: Dumb Undergraduate question 20 Nov 2003 09:11:55 AM
"Timtro" <timtro@rogers.com> wrote in message news:<lp0vb.67746$j1d.5148@news04.bloor.is.net.cable.rogers.com>...

Hi. I found a question in my first year text book that I can't answer. I'm
sorry to bother you all, but I am simply too embarassed to ask my prof. I
really should know this by now

If I were to put a pendulum in a accelerating truck, how would it affect the
period?

The pendulum finds itself in a new acceleration field
one which is the vector sum of g and a horizontal component
due to the truck motion.


The question also asks about a pandulum in an accelerating elivator, but I
assumed that you simply add the acceleration due to gravity to the elevators
acceleration vector and use that instead of g in the equation for period
(T=2Pi*sqrt(r/g)).

Yes. Same as with the truck. Use vector addition to
get the magnitude of g + a. Vector addition also tells
you that the equilibrium position is no longer straight
down.
- Randy
.

User: "Gregory L. Hansen"

Title: Re: Dumb Undergraduate question 20 Nov 2003 09:43:06 AM
In article <lp0vb.67746$j1d.5148@news04.bloor.is.net.cable.rogers.com>,
Timtro <timtro@rogers.com> wrote:

Hi. I found a question in my first year text book that I can't answer. I'm
sorry to bother you all, but I am simply too embarassed to ask my prof. I
really should know this by now

If I were to put a pendulum in a accelerating truck, how would it affect the
period?

The question also asks about a pandulum in an accelerating elivator, but I
assumed that you simply add the acceleration due to gravity to the elevators
acceleration vector and use that instead of g in the equation for period
(T=2Pi*sqrt(r/g)).


The one with the truck would be just like the one in the elevator. Take
the vector sum of Earth's gravitational acceleration and the truck's
acceleration and use that for your g'.
--
"Let us learn to dream, gentlemen, then perhaps we shall find the
truth... But let us beware of publishing our dreams before they have been
put to the proof by the waking understanding." -- Friedrich August Kekulé
.


  Page 1 of 1

1

 


Related Articles
 

NEWER

pg.1612     pg.1232     pg.940     pg.716     pg.544     pg.412     pg.311     pg.234     pg.175     pg.130     pg.96     pg.70     pg.50     pg.35     pg.24     pg.16     pg.10     pg.6     pg.3     pg.1

OLDER