Determine the x, y, z components of reaction at A and B 

Why is there no Ay ?

It's because in the text book he got the problem from only asks for components of reaction at A and B. The problem isn't written on screen here for some reason. He reads it out loud at the beginning though - " The bar AB is supported by two smooth collars. At A the connection is with a ball-and-socket joint and at B it is a rigid attachment. If a 50-lb load is applied to the bar, determine the x, y, z components of reaction at A and B."

Why is there no Ay?

Because the collar does not restrict axial movement of the pipe passing through it.

did you figure it out?

@@OldestDream4951 why is he ignoring all the other support reactions????

Quick break down of these types of questions Look at the types of attachments/connections/pins whatever and look at what is restricted vs not, Looking at A we see okay since its a slider along Y axis it can move freely along Y and if it wasnt attached should be able to rotate along the Y axis In short at A it will be restricting forces in the X and Z direction, and also restrict movement in the x and y rotations Looking at B since it's angled there will be forces and moments in all directions because its not in line with our cartesian axes

The answers my text book had/ said were The bar AB is supported by two smooth collars. At A the connection is with a ball-and-socket joint and at B it is a rigid attachment. If a 50-lb load is applied to the bar, determine the x, y, z components of reaction at A and B. [Ax = 16.7 lb, Bx = 16.7 lb, By = 50 lb, M_Bx = 300 lb ft, M_Bz = 0, M_By = 900 lb ft] and i figure its only referring to magntiudes