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## GR0877 Problem 59

PROBLEM STATEMENT: This problem is still being typed.

SOLUTION: (C) Elimination of choices. (A): wrong, the period must depends on $a$; (B): for a particular case $a = g$ the period blows up — wrong; (C): reasonable; (D): for $a = 0$, $T = 0$ — wrong; (E): for $a = 0$, $T$ blows up — wrong. Thus, choice (C).

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1. 15.10.2011 at 00:57

A direct solution without elimination of others: In the elevator’s frame, there is an effective gravitational acceleration $g'=g+a$. Therefore, the period is $2 \pi \sqrt{l/g'}= 2 \pi \sqrt{\frac{l}{g+a}}$

2. 06.11.2011 at 20:50

As PineApple notes, the important thing is that the accelerating frame ADDS to the acceleration. If the elevator were accelerating downwards the answer would be B. Then if a=g, then the period would in fact blow up, since the pendulum would not oscillate.

3. 01.04.2014 at 05:09

At first, I thought it meant g = positive if we treat upward acceleration to be negative, so if that’s the convention B is correct.

4. 29.08.2016 at 09:43

Equivalence principle. That is all.