Rotational motion: Number of revolutions before a flywheel comes to rest

Join the discussion
Registration is free. Start your own thread to ask a follow-up.
2 replies · 2K views
Bolter
Messages
262
Reaction score
31
Homework Statement
Working out number of revolutions before flywheel comes to rest
Relevant Equations
Rotational equivalent of SUVAT equations
Hi there

I have been having a go at this question and I'm uncertain if my answer to part b) is valid?

Screenshot 2019-12-22 at 21.29.47.png


IMG_3545.JPG

IMG_3546.JPG


The problem is when I plug this into the calculator I get 6.379... revs however this doesn't make sense to me. 2*pi is roughly 6.28 radians so doing 4.061... rads / 6.28 rads = 0.647 revs

Thanks!
 
Last edited by a moderator:
Physics news on Phys.org
I get 0.646 revs. Redo the calculation or use a spreadsheet for independent confirmation.
 
  • Like
Likes   Reactions: Bolter
kuruman said:
I get 0.646 revs. Redo the calculation or use a spreadsheet for independent confirmation.

Ok thanks. I just checked on an online calculator and get the same now as you. I suppose my calculator is just malfunctioning and acting really dodgy :rolleyes: