find the unknown quantities:

Question

anonymous · Answer

wat the chooses

anonymous · Answer

|dw:1392409615989:dw|

anonymous · Answer

i really have troubles with this

anonymous · Answer

This is really physics, but I can help. 
Acceleration due to gravity varies from class to class, but is usually about 10 m/s.
To find Fgrav, you multiply acceleration due to gravity by mass. 10*6=60N
Fnorm is the same as Fgrav on a flat surface, just up instead of down.
Does it have a Velocity? I can't determine anything else without one.

unklerhaukus · Answer

im not sure i understand the diagram, is that a block resting on a plane?

anonymous · Answer

yes

unklerhaukus · Answer

gravitational force is F_g=-mg

the object is not moving so the normal force cancels this  F_N=mg

unklerhaukus · Answer

the friction force is F_f = -µ F_N

where µ is the friction coefficient 



the applied force F_a must balance this for the object to remain motionless

unklerhaukus · Answer

(i have choosen upwards and right to be positive)