Register to reply

Pendulum clock when taken to moon

by utkarshakash
Tags: clock, moon, pendulum
Share this thread:
utkarshakash
#1
Dec25-12, 01:30 AM
PF Gold
P: 833
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).
Phys.Org News Partner Science news on Phys.org
Flapping baby birds give clues to origin of flight
Prions can trigger 'stuck' wine fermentations, researchers find
Socially-assistive robots help kids with autism learn by providing personalized prompts
lewando
#2
Dec25-12, 01:38 AM
PF Gold
P: 1,053
The period is longer so the frequency must be...
sankalpmittal
#3
Dec25-12, 01:41 AM
sankalpmittal's Avatar
P: 758
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
#4
Dec25-12, 09:40 AM
PF Gold
P: 833
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
#5
Dec25-12, 09:57 AM
PF Gold
phinds's Avatar
P: 6,329
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 ?


Register to reply

Related Discussions
Pendulum clock Mechanical Engineering 5
Pendulum Clock Special & General Relativity 4
Reading of a pendulum clock from the earth to the moon Introductory Physics Homework 3
Time When Pendulum Clock is Put on Moon? Introductory Physics Homework 7
Pendulum clock Introductory Physics Homework 4