A20-lb force acts to the west while an 80-lb force acts 45° east of north. the magnitu 80 lb 70 lb 067 lb 100 lb

option C

Explanation:

given,

force act on west  = 20 lb

force act at 45° east of north = 80 lb

magnitude of force = ?

∑ F y  =  80 cos 45⁰

    F y =  56.57 lb

magnitude of forces in x- direction

∑ F x = -20 + 80 sin 45⁰

        = 36.57 lb

net force

F =

F =

F = 67.36 lb≅ 67 lb

hence, the correct answer is option C

i think it because equal matrices have equal dimensions, only square matrices can be symmetric. for all indices and . every square diagonal matrix is symmetric, since all off-diagonal elements are zero. in linear algebra, a real symmetric matrix represents a self-adjoint operator over a real inner product space.

answer: option c.

explanation: