High School Physics Question!


by Dunkaroos
Tags: physics, school
Dunkaroos
Dunkaroos is offline
#1
Apr30-06, 09:02 PM
P: 20
Please help. I'm having difficulty with this problem. My book offers an answer but no explanation. Thanks for helping.


I have the answer if you guys want it.
Attached Thumbnails
physics7la.jpg  
Phys.Org News Partner Science news on Phys.org
NASA's space station Robonaut finally getting legs
Free the seed: OSSI nurtures growing plants without patent barriers
Going nuts? Turkey looks to pistachios to heat new eco-city
pizzasky
pizzasky is offline
#2
Apr30-06, 11:42 PM
P: 167
Note that the wave is moving to the right. Hence, translate the whole curve slightly to the right to determine where point P will eventually be.
kudos213
kudos213 is offline
#3
May1-06, 06:59 AM
P: 16
Yes, but doesn't each point on the wave maintain it's position in the positive x direction? It's only the y component of each point which changes. Anyone else have any idea?

Hootenanny
Hootenanny is offline
#4
May1-06, 07:09 AM
Emeritus
Sci Advisor
PF Gold
Hootenanny's Avatar
P: 9,789

High School Physics Question!


Quote Quote by kudos213
Yes, but doesn't each point on the wave maintain it's position in the positive x direction? It's only the y component of each point which changes. Anyone else have any idea?
Yes, the point P oscillates only in the y direction, so as the wave moves to the right, will point P move up or down?

~H
kudos213
kudos213 is offline
#5
May1-06, 07:15 AM
P: 16
negative y hat
Hootenanny
Hootenanny is offline
#6
May1-06, 07:17 AM
Emeritus
Sci Advisor
PF Gold
Hootenanny's Avatar
P: 9,789
Quote Quote by kudos213
negative y hat
Yes, I suggest we let the OP finish of the question.

~H
kudos213
kudos213 is offline
#7
May1-06, 07:20 AM
P: 16
word...i'm still new here i.e. learning the ropes. how could we mathematically solved this question?
Hootenanny
Hootenanny is offline
#8
May1-06, 07:22 AM
Emeritus
Sci Advisor
PF Gold
Hootenanny's Avatar
P: 9,789
Quote Quote by kudos213
word...i'm still new here i.e. learning the ropes. how could we mathematically solved this question?
You couldn't, there is no data given (velocity/ displacement / time).

~H
DaveC426913
DaveC426913 is offline
#9
May1-06, 08:51 AM
DaveC426913's Avatar
P: 15,325
This question actually somewhat ambiguous, and as such the OP might get the wrong advice and answer.

Depending on how you interpret "point P", your answer will be different!
a] Point P is a physical point on the rope.
b] Point P is an imaginary point on the wave.

Pizzasky interpreted it as a], but others interpreted it as b].

I'm am 99.9% certain a] is correct. So, yes, follow Kudos and Hoot's guidance.
Hootenanny
Hootenanny is offline
#10
May1-06, 08:59 AM
Emeritus
Sci Advisor
PF Gold
Hootenanny's Avatar
P: 9,789
Quote Quote by DaveC426913
This question actually somewhat ambiguous, and as such the OP might get the wrong advice and answer.

Depending on how you interpret "point P", your answer will be different!
a] Point P is a physical point on the rope.
b] Point P is an imaginary point on the wave.

Pizzasky interpreted it as a], but others interpreted it as b].

I'm am 99.9% certain a] is correct. So, yes, follow Kudos and Hoot's guidance.
The OP said they have the correct answer, it would be helpful if he/she could post it to clear the matter up. But I agree with Dave, it is an ambiguous question, I was assuming point P is a physical point on the wave.

~H
skywolf
skywolf is offline
#11
May1-06, 10:47 AM
P: 80
if the wave is going to the right, then shouldnt the answer be c?
......
maybe im missing something
Hootenanny
Hootenanny is offline
#12
May1-06, 11:13 AM
Emeritus
Sci Advisor
PF Gold
Hootenanny's Avatar
P: 9,789
Quote Quote by skywolf
if the wave is going to the right, then shouldnt the answer be c?
......
maybe im missing something
That is what we were discussing, I'll refer you to posts #4,5,6,7

~H
Dunkaroos
Dunkaroos is offline
#13
May1-06, 05:40 PM
P: 20
The answer key gives choice C.

Anyone care to explain? Thank you all.
DaveC426913
DaveC426913 is offline
#14
May1-06, 06:10 PM
DaveC426913's Avatar
P: 15,325
OK. That clears up what they're asking. Point P is a physical point on the rope. Pretend it's a spot of paint.

Now, as the wave travels down the rope, how will that spot of paint move?

Think of this: the rope is tied off the right side to a lamppost. Your friend is off to the left, holding the rope, waving it up and down, creating the wave. (Note that the rope does not actually go anywhere - he can wave all he wants, but the rope will remain in our field of vision).

NOW what will the spot of paint do?


Register to reply

Related Discussions
Need help with High School Physics PLEASE! Introductory Physics Homework 1
Acceleration Question for a High School Physics Lab Introductory Physics Homework 1
Question About Physics Homework (High School Physics) Introductory Physics Homework 9
High School Physics Question Introductory Physics Homework 4
Science Bowls/Competitions for US High School and Middle (Jr High) School Students Academic Guidance 0