Find the magnitude of the moment of the force about AB, BC and CA

Determine the magnitude of the moment of the force
F = {50i - 20j - 80k} N about the base line AB of the tripod.

Determine the magnitude of the moment of the force
F = {50i - 20j - 80k} N about the base line BC of the tripod.

Determine the magnitude of the moment of the force

[justaguy]

Please keep up these videos!! I got a 100% on my first statics exam thanks to you! Thank you for putting in the time to help everyone.

[marramable]

Why did you use AD instead of BD for part 1? Why use CD instead of BD for part 2? same for part 3?

Your videos are extremely helpful and are helping me get an A in statics. Thanks!

[johnan]

Problem 5.32 Determine the magnitude of force at the pin A and in the cable BC needed to support the 600-lb load. Neglect the weight of the boom AB.

[makon]

what if you set the unit vector as AC instead of CA

[SebaxMods]

For the radius I need to use a point inside the diagram, I mean, A, B, C & D or might I use from the origin to C?

[MkMk-huzj]

Thanks for solution... But I didn’t understand why did you put the (+) top of the j direction column ? Is the order like this +, -, +

[HGxLegend]

Question. In regards to Ubc(CDXF). I did vector CB instead of BC, in the end I got the same answer just with opposite sign that you got. Since we absolute value the magnitude in the end, does it matter in other cases if we do CB instead of BC? Thanks. And by the way I love your way of using matrices so solve problems. Thanks again!

[ernestinamartinez]

I think the second solution is incorrect because rCD=0i+2j+4k and he put 0.5 instead of 0 for the i. my answer was -130.44Nm

[misterwebb]

Apparently the example is wrong because I had the same problem on my hw and did it the same way you did and got it wrong