00:01
In this question, you have the disk that rose without sleeping and it has angular velocity, 2 radiance per second, angular acceleration, 4 radiance per second square.
00:09
That's the instance shown.
00:11
We need to determine the acceleration of points a and b on the link and links angular acceleration at this instance.
00:21
Point a is at the periphery of the disk.
00:26
Okay, so there's no slipping.
00:28
Which means that for the disk the ic, the instantaneous center of zero velocity is at at point d here.
00:54
Okay, so this is the ic for the disc, okay? then from based on this on this analysis we expect va to be pointing to the right you also expect that we be is also pointing to the right okay since ba and bb are parallel the instantaneous center zero velocity of the link ab is at infinity so, okay, so this also means that omega ab is equal to 0.
02:09
And then we can determine va to be equal to r, i see of the disk to a times omega of the disk.
02:31
And then along the i direction.
02:34
So this is 0 .3 times 2i.
02:43
So this is 0 .6i meters for a second.
02:49
Then we can find reb is also 0 .6i meters per second.
02:58
Okay, next we find the acceleration of point a.
03:03
Okay, acceleration of point a, okay, before that you need you need to find ac, you need to find ac, okay, ac is going to be alpha r, i, which is 0 .15 times 4, i which is 0 .6, i meters per second square.
03:41
So acceleration of point a is a is ac.
03:46
Plus alpha cross r of a relative to c minus omega square times r of point a relative to c.
03:59
Okay so this is equal to 0 .6i plus 4k cross 0 .15 j minus 4 times 0 .15 j.
04:17
Okay so we have 1 .2.
04:20
To i minus 0 .6 j...