It is suggested the timing uncertainty for one revolution is 0.5 ms owing to the precision of the photogate timer. Indeed, the device is very precise; timing a rotation based on the precise measurement of the interval between light first passing through the hole in the disc and the next moment it does so (on the completion of a rotation).
Is this a correct estimate for the uncertainty in time T that we take as the time for one revolution from rest ?

Question

It is suggested the timing uncertainty for one revolution is 0.5 ms owing to the precision of the photogate timer. Indeed, the device is very precise; timing a rotation based on the precise measurement of the interval between light first passing through the hole in the disc and the next moment it does so (on the completion of a rotation).  
 Is this a correct estimate for the uncertainty in time T that we take as the  time for one revolution from rest ?

Answer

No, we should consider light travel time through the hole.

Answer

No, we should consider also human response time

Answer

No, we should note that there is a timing error on the start and end and double this estimated uncertainty

Answer

Yes, the gate times based on light and as such is as close to flawless as we can get. In fact, if anything the uncertainty should likely be smaller if only the photogate displayed more digits.

Answer

No, starting from rest is not the same as any rotation. While the timer is precise in terms of a rotation, we cannot guarantee that the time we get is the time of a rotation from rest.

Crowdly

It is suggested the timing uncertainty for one revolution is 0.5 ms owing to the...

Want instant access to all verified answers on learning.monash.edu?