Vertical circular motion with accelerating centre

[subhradeep mahata]

Homework Statement

Suppose, a ball of mass m has to just complete the vertical circular motion when its point of suspension is accelerating vertically upwards with an acceleration g/3. We have to find that particular minimum speed at the extreme bottom that must be given to it so that it just completes the vertical circle.

Relevant Equations

General laws of motion and energy conservation

I can do the problem if the centre is fixed. The steps are:
1) Assuming tension in the string is zero at the top most position, we calculate the velocity at top most position by mv²/R = mg
2)Now, we simply apply mechanical energy conservation when the ball is at the top and bottom positions respectively and find out the required speed.
But, now as the centre is accelerating, I am confused. Do I have to apply pseudo force and proceed in the same way?
Please explain it to me.
Thanks.

 

[haruspex]

Do I have to apply pseudo force and proceed in the same way?

The use of non inertial frames (and hence pseudo forces) is certainly an option, and probably the easier way here.

 

[subhradeep mahata]

So, I should apply pseudo force and follow the two steps, isn't it?

 

[haruspex]

So, I should apply pseudo force and follow the two steps, isn't it?

Yes.