Answer:
A) 111 N
B) F_net = 0 N
C) 100 N, in the opposite direction of the motion.
D) μ = 0.3274
Explanation:
A) The component of the trunks weight acts parallel to the plane but in the vertical direction and so;
W = Fsin θ
W = 325 sin 20
W = 325 × 0.3420
W ≈ 111 N
B) We are told the trunk is moving with a constant velocity and for this reason the sun of the forces will equal to zero.
Thus; F_net = 0 N
C) Since the kinetic friction force needs to balance the component of the weight, the magnitude is;
F_f = 211 - 111 = 100 N
The direction will be in the opposite direction since it's against the motion.
D) From friction formula, we know that;
F_f = μW cos θ
100 = μ × 325 × cos 20
μ = 100/(325 × cos 20)
μ = 0.3274
