This is best explanation of engineering mechanics concepts 👍, thanks a lot. Please make videos on other topics also like virtual work and all the other mechanics topics
Hi, No, you can't add 150 N forces. The idea behind adding 100 N forces is to create two couples of 100 N forces instead of one. Compare method 3 with method 2 ==> In method 2, there is a single couple with forces lying on an inclined plane (formed by the two forces and the line DE) and so its moment vector is normal to this plane. You've to use little imagination and trigonometry to resolve this moment vector along coordinate axes so that you can then add it to another moment vector. Method 3 makes the solution easier... no trigonometry stuff ... By adding 100 N forces at point A, you build two couples instead of one. What's the advantage? You can easily visualize that the couple moments are along y and z axes. No new concept... little manipulation of vectors to either cut down on 'time to solve' or lessen visualization stress. Hope this helps!
You may like to watch this video ruclips.net/video/XNGi73GZ_YA/видео.html (basic concepts of couples) to clear your doubts. Moment of a force/couple is the tendency to rotate the body on which it acts. A couple is simply a pair of equal forces but oppositely directed.
Hi Ayam: That is so because the 100 N force acting at point E points in negative x-direction. So in vector form you'll write -100 i. Hope that clarifies the matter.
This is best explanation of engineering mechanics concepts 👍, thanks a lot.
Please make videos on other topics also like virtual work and all the other mechanics topics
love method 3! never saw this before
hi, for method 3. Why must we attach two equal & opposite direction forces of 100N? Can it be 150N?
Hi,
No, you can't add 150 N forces. The idea behind adding 100 N forces is to create two couples of 100 N forces instead of one.
Compare method 3 with method 2 ==> In method 2, there is a single couple with forces lying on an inclined plane (formed by the two forces and the line DE) and so its moment vector is normal to this plane. You've to use little imagination and trigonometry to resolve this moment vector along coordinate axes so that you can then add it to another moment vector.
Method 3 makes the solution easier... no trigonometry stuff ... By adding 100 N forces at point A, you build two couples instead of one. What's the advantage? You can easily visualize that the couple moments are along y and z axes. No new concept... little manipulation of vectors to either cut down on 'time to solve' or lessen visualization stress.
Hope this helps!
@@VectorInMotion Such a good explanation! I appreciate the help. Keep making amazing videos!! :)
thank you very much
for method 3
For Method #1 I THINK it should be -60i + -30j + 20k please let me know if I'm wrong. Thank you for your help.
No you are wrong you multiply the j components by a negative
Yes, that is incorrect. The expression given in the video is the correct one.
but i need further explanation the difference between the resultant couple and resultant mument about any point
You may like to watch this video ruclips.net/video/XNGi73GZ_YA/видео.html (basic concepts of couples) to clear your doubts. Moment of a force/couple is the tendency to rotate the body on which it acts. A couple is simply a pair of equal forces but oppositely directed.
in the first method n, why is the 100 N force negative
Hi Ayam: That is so because the 100 N force acting at point E points in negative x-direction. So in vector form you'll write -100 i. Hope that clarifies the matter.
Super sir
my lord -excellent excelent excelent -- writing is very very small -eye strain
Good you pointed it out. Shall keep in mind in future.
I love it
Hi Pankaj; Thanks for your comments and I'm glad you find it useful.