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)).

"Timtro" wrote in message
e.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".

"Greg Neill" wrote in message
...
"Timtro" wrote in message
e.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.

"Timtro" wrote in message le.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

"Timtro" wrote in message le.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

In article gers.com,
Timtro 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