Brainache revisited

The goody bag top spinning atop my laptop..

If the two photographs below were taken with an exposure of 1/60th of a second,

How many rotations a minute was the top doing?

he he he...

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Comments

[Me]

1425 RPM?

[just another mommy]

My head hurts! :)
I never do things without incentive...so soweee!

[Anonymous]

im sorry but what is this? pl explain.

It looks like an electronic pambaram to me...

RS

[Sundar Narayanan]

RS, it is a pambaram with an LED inside that lights up when the top goes above a certain minimum speed..

JAM, I know.. no incentive here..

me, I used a protractor and got 160 degree angle lit..
that is 160/360 = .444 of a rotation at 1/60 of a second (ie. 0.0166 seconds).

so it would make 26.66 rotations per second (that is .444/.0166666)

26.66*60 = 1600 RPM..

you are very close.. probably you measured 130 degree angle..

you should get some geek award.. unfortunately no time to slap some graphics and make you one..

:)

[Me]

the second image had 24 sectors for 360 degrees....

9.5 sectors had light on them ...so i assumed 9.5*(360/24) = 142.5 degrees

doing the math like u did...it came out to 1425 rpm...