Why Does the Pendulum Angle Calculation Show 60° Instead of 30°?

Thread starter cupid.callin
Start date Mar 23, 2011
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Accelerating Pendulum

AI Thread Summary

The discussion centers on a pendulum angle calculation where the user arrives at an angle of 30° using the equations Tcosθ = mg and Tsinθ = mao, leading to tanθ = ao/g = 1/√3. Despite this calculation, the textbook states the angle should be 60°. The user expresses frustration, noting their consistent accuracy in previous problems and questioning the textbook's reliability. The conversation highlights a potential misunderstanding of the problem or a misinterpretation of the forces involved. Ultimately, the discrepancy between the calculated angle and the textbook answer remains unresolved.

Mar 23, 2011

cupid.callin

Homework Statement

attachment.php?attachmentid=33446&stc=1&d=1300915884.jpg

The Attempt at a Solution

Here my figure showing forces:

attachment.php?attachmentid=33447&stc=1&d=1300915884.png

SO here,

Tcosθ = mg
Tsinθ = ma_o

so tanθ =a_o/g = 1/√3

so θ = 30^o, right?

but it answer says its 60^o

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Mar 23, 2011

vipulgoyal

books wrong... i also got the same asnwer

Mar 24, 2011

cupid.callin

that can't be
book hasn't been wrong ever till now (and i have done like 80% of it)

Mar 24, 2011

cupid.callin

Does everyone think that answer is 30 ?

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