- #1

- 63

- 0

Three forces with magnitudes [tex]F_a, F_b, F_c [/tex] act on a point mass, pulling in

By taking the cross product with

and find two similar equations (involving [tex]F_a[/tex] and [tex]F_c[/tex], and [tex]F_a[/tex] and [tex]F_b[/tex], respectively).

I'm quite stuck here, i dont think i understand fully. The only mere working i can muster is:

[tex] a \times (a \times b) = (a.b)a - (a.a)c [/tex]

[tex] a \times (c \times a) = (a.a)c - (a.c)a [/tex]

Can anyone help me out?:uhh:

**unit**directions**a, b, c,**respectively. Thr forces are in 'equilibrium' which means that[tex]F_aa + F_bb + F_cc = 0[/tex]

By taking the cross product with

**a**, show that[tex]F_b(a \times b) = F_c(c \times a)[/tex]

and find two similar equations (involving [tex]F_a[/tex] and [tex]F_c[/tex], and [tex]F_a[/tex] and [tex]F_b[/tex], respectively).

**My Work**I'm quite stuck here, i dont think i understand fully. The only mere working i can muster is:

[tex] a \times (a \times b) = (a.b)a - (a.a)c [/tex]

[tex] a \times (c \times a) = (a.a)c - (a.c)a [/tex]

Can anyone help me out?:uhh:

Last edited: