and these are few more questions if someone can help~

1. what's the meaning of N50 degree W?

2.a wrench 30cm lies along positive y-axis and grips at origin.a force is applied in direction (0,3,-4) at the end of wrench.find the magnitude of force to produce torque of 100Nm. i tried doing this but how to find the angle of the force?

3. let P be a point not on line L which passes thru points Q and R.Show the distance from point P to line L is :

distance = I axb I / I a I where a = QR and b = QP

*the symbol 'I' is modulus.

4.find lengths of medians of triangles with vertices A(1,2,3), B(-2,0.5)
and C(4,1,5)

5.find equation of largest sphere with center (5,4,9) in first octant.
is the answer (x-5)^2 + (y-4)^3 + (z-9)^2 = 0?