00:01
Projected up in a slope of theta and it returns to its initial position with half of its initial speed and we want to show that the coefficient of static fissure can be written as 350s of the tangent of the angle so we just need to apply newton's second law for the block and use the boundary condition that we are given first we need to draw the free biode diagram that in the slope, you grab the outsponts down.
00:36
We have the normal force in the direction of the slope.
00:40
And we have the friction force either pointing to the up or down depending on the when it's going up or down.
00:52
So we have here, fk when it's going up, and fk points to this direction when down.
01:06
So let's use the block, separate the neutral equation in two parts when the block is going up and when the block is going down.
01:15
So up, we have mg sine of theta plus f k is equal to m a up and m is equal to m g cosine of theta.
01:29
This gives us a up is equal to g sine of theta plus mu k cosine of theta.
01:39
Mucatg, whole sign of theta.
01:42
And when it's going down, we have mg sine of theta minus fk is equal to m a down.
01:54
And n is again mg hosine of theta.
01:57
So it's just difference in the definition here.
02:04
So we have a down is equal to g sine of theta minus mu k g, hosine of data...