00:01
Hi, here in this question we are given that the force f of xyz is equal to z i cap plus x j cap plus y k cap and the value is from 3 .00 to 0 pi by 2 and 3.
00:19
Now here we need to find the work done across a straight line and a halix.
00:23
So the work done on a straight line will be the point v equals to minus 3 pi by 2 and 3.
00:30
So x equals to 3 minus 3 t, y equals to pi by 2 times of t and z equals to 3 t, where 0 less than or equal to t less than or equal to 1.
00:41
So differentiating we have d x equals to minus 3dt, dy equals to pi by 2 and dz equals to 3dt.
00:51
Now, so the work done would be integration over the curve c, f .t, ds.
00:57
Now this is again equal to integral over c.
01:00
P of d x plus q of d y plus r of d z therefore here in our case we have wakdon equals to integration of 0 to 1 z d x plus x d y plus y d z therefore this is again equal to integration of 0 to 1 3 t multiplied with 3 d t plus 3 minus 3 t multiplied with pi by 2 times of d t plus pi by 2 times of t multiplied with 3d t now on simplifying this and integrating we have 9 t plus 3 pi by 2 and the value is from 0 to 1 now giving value and simplifying this here we can say that we got our first answer as work done equals to 3 pi by 2 minus 9 now similarly we need to calculate in a system of a halix so for halix here we have x equals to 3 cost t y equals to t and z equals to 3 sine t.
02:10
Therefore, here we have dx equals to minus 3 sine t, d -y equals to dt and dz equals to 3 cost t d t...