Answer
Ffs = 251 N
Fn = 691 N
Explanation
Take the y direction to be normal to the ramp and the x direction to be parallel to the ramp. The angle of the ramp is 20°, so the angle that the weight vector makes with the normal is also 20°. Therefore:
Fgx = Fg sin 20°
Fgy = Fg cos 20°
Sum of the forces in the x direction (parallel to the ramp):
∑F = ma
Ffs − Fgx = 0
Ffs = Fgx
Ffs = Fg sin 20°
Ffs = 735 sin 20°
Ffs ≈ 251
Sum of the forces in the y direction (normal to the ramp):
∑F = ma
Fn − Fgy = 0
Fn = Fgy
Fn = Fg cos 20°
Fn = 735 cos 20°
Fn ≈ 691
