## Abhishekguptapsychoman Group Title a pendulum is attached to roof of train , which is accelerating uniformly, then time period of pendulum will decrease or increase?? 10 months ago 10 months ago

• This Question is Open
1. Shikhar2408

the time period will remain the same.. the bob will do small oscillations but we know that $T=2\Pi \sqrt{l/g}$ so in this eqn.there is no amplitude..therefore T is not related to the amplitude... hence time period remains same..

2. Shikhar2408

T resembles the time period of the bob.. by the way which text book are you studying?

3. Vincent-Lyon.Fr

Time period will decrease, since new weight relative to train coach will be bigger: mg* with $$\vec {g*}=\vec g-\vec a$$ and $$g^*=\sqrt{g^2+a^2}$$ $$T^*=2\pi \sqrt{l/g^*}$$

4. Will-i-am

according to Einstein, the faster you go the heavier you are so the time period WILL DECREASE

5. Vincent-Lyon.Fr

This is not a relativistic train :) So there is no increase in the mass of the pendulum.

6. Will-i-am

lol ANYTHING that's moving at ANY speed will increase in mass relative to a non-moving object

7. iamsmarterthanyou

just to be nerdy lol

8. iamsmarterthanyou

btw i am Will-i-am i just got my account like deleted

9. Vincent-Lyon.Fr

Increasing the mass without increasing the restoring force would make the period longer. On the accelerating train, you can simulate an increase in gravity, producing an increase in the restoring force without changing the inertia of the bob. The result is a faster motion / shorter period.

10. ghHabib

if you are in the real case, the periode of the pendulum will decrease but that due to the effect of friction with the air ,in the opposite when we neglect the friction the periode remain constant .

11. Vincent-Lyon.Fr

@ghHabib The decrease in the period has nothing to do with air resistance (or its absence).