Pendulum clock when taken to moon


by utkarshakash
Tags: clock, moon, pendulum
utkarshakash
utkarshakash is offline
#1
Dec25-12, 01:30 AM
P: 658
1. The problem statement, all variables and given/known data
A pendulum clock that keeps correct time on the earth is taken to the moon. It will run

a) at correct rate
b)6 times faster
c)√6 times faster
d)√6 times slower

2. Relevant equations

3. The attempt at a solution
[itex]T_{earth} = 2\pi \sqrt{\dfrac{L}{g}} \\
T_{moon} = 2\pi \sqrt{\dfrac{L}{g/6}} [/itex]

Dividing i) by ii)

[itex]\dfrac{T_{earth}}{T_{moon}} = \frac{1}{√6} \\
T_{moon} = √6T_{earth} [/itex]

This implies option c) is correct but my book says it is option d).
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lewando
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#2
Dec25-12, 01:38 AM
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The period is longer so the frequency must be...
sankalpmittal
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#3
Dec25-12, 01:41 AM
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Quote Quote by utkarshakash View Post
1. The problem statement, all variables and given/known data
A pendulum clock that keeps correct time on the earth is taken to the moon. It will run

a) at correct rate
b)6 times faster
c)√6 times faster
d)√6 times slower

2. Relevant equations

3. The attempt at a solution
[itex]T_{earth} = 2\pi \sqrt{\dfrac{L}{g}} \\
T_{moon} = 2\pi \sqrt{\dfrac{L}{g/6}} [/itex]

Dividing i) by ii)

[itex]\dfrac{T_{earth}}{T_{moon}} = \frac{1}{√6} \\
T_{moon} = √6T_{earth} [/itex]

This implies option c) is correct but my book says it is option d).
Use concept ,

T [itex]\alpha[/itex] 1/√g

As √g reduces by √6 on moon , this implies time period on moon will be √6 times that of earth , as you got. You interpreted your answer wrongly. If the time period increases , pendulum will oscillate slower or faster for a given displacement of the bob ?

utkarshakash
utkarshakash is offline
#4
Dec25-12, 09:40 AM
P: 658

Pendulum clock when taken to moon


Quote Quote by sankalpmittal View Post
Use concept ,

T [itex]\alpha[/itex] 1/√g

As √g reduces by √6 on moon , this implies time period on moon will be √6 times that of earth , as you got. You interpreted your answer wrongly. If the time period increases , pendulum will oscillate slower or faster for a given displacement of the bob ?
Thanks for pointing out my mistake
phinds
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#5
Dec25-12, 09:57 AM
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P: 5,718
Quote Quote by utkarshakash View Post
[b]

This implies option c) is correct but my book says it is option d).
Forget the math for a minute and just think about it logically. Would you really expect a pendulum clock when moved to lower gravity to have the pendulum swing FASTER? Really ?


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