00:01
For this problem, we have a box with mass 40 kilograms hanging motionless from two ropes as shown in the figure, where the angle here is 38 degrees.
00:09
We are asked to choose the boxes of the system.
00:12
We're told that the x -axis runs to the right and the y -axis runs up and the z -axis is out of the page.
00:18
In part a, we are asked to draw a free body diagram for the box.
00:22
So we have the force of gravity pulling downwards.
00:26
We have the force, i'll call it ft1, pulling up into the right with an angle of 38 degrees, and we have, or excuse me, that last one should be ft2, actually, since that is labeled as rope 2.
00:49
And then we have a force pulling to the left called, or which we'll call ft1.
00:59
For part b, we are asked, is dp by d .p.
01:03
Of the box zero or non -zero.
01:06
Well, since we are told that it is hanging motionless, we have that momentum or the change in momentum would have to be equal to zero.
01:17
For part c, we are asked, what is the y component of the gravitational force acting on the block? so that is going to be equal to mass times acceleration, so that's 40 kilograms times 9 .8 meters per second squared.
01:36
And that will give us a result here of, or actually that should be negative 9 .8 since we're going down, that will give us a result of about 392 newtons.
01:48
Then for part d, we are asked, what is the y component of the force on the block due to rope 2? so what we have is we first need to note that fty would have to be equal to, since we're staying with absolutely no motion...