00:01
Let's see the free body diagram of the situation here.
00:12
This is a cartoon of mass 13 kg.
00:19
Now it has been pulled up by a rope using this mechanism.
00:36
Now let's suppose the block starts from here and this went up on the net.
00:47
This particular length is given as 5 .2 meter.
00:53
Now this is 30 degree.
00:54
So this particular length, that is h here, will be equals to 5 .2 into sign 30, that will be equal to 2 .6 meter.
01:06
Walk down by the tension in the rope will be equal to t into distance travel along this direction, that is t, this force.
01:22
And the distance is travel in this direction that is equal to 5 .2 that is t into 5 .2 t is given as 72 new 10 so 72 into 5 .2 so this is equal to 374 .4 jule so this is a work done by the tension in the road now gravity work done by the gravity force in the question, if you see this block, the gravity acts in the downward direction, whereas the block holds in this particular direction.
02:07
So we can write here that the work done by the gravity mg into the distance travel into cosine of this particular angle.
02:22
Let's say it is denoted by theta.
02:25
Now theta is equal to here 90 plus 30 degree, that is 120 degree.
02:31
So we can write work done by gravity equals to mg into cost 120 into distance.
02:47
Now distance is here 5 .2 meter.
02:52
So 13 into 9 .81...