00:01
Hello, in equation a we have to calculate acceleration of the block down the plane.
00:06
Let's make the sketch.
00:08
Let's show the forces acting on this block.
00:16
Normal reaction, tension and the result of friction force and gravity.
00:23
And the block experiences only tension.
00:27
Then, m a, or actually m g, sin theta minus mu k, m g, cosine theta minus tension equals to m a.
00:40
On the other hand, for the pulley, tension times radius of the pulley is angle of acceleration times moment of inertia.
00:50
It means that this tension is mass of the pulley, acceleration over 2.
01:00
Overall, acceleration is m g, sin theta minus mu k, m g, cosine theta divided by mass of the block plus half mass of the pulley.
01:19
And now let's rewrite it...