Problem 6-47 Dynamics with friction - Part 4 - A

A boy drags a huge garbage can of mass \(27\; kg\) along a horizontal driveway at a constant speed of \(1.8\; m/s\). He exerts a force of \(112\; N\) at an angle of \(27^\circ\) above the horizontal. Determine the coefficient of kinetic friction between the can and the driveway.

Accumulated Solution

FBD with all angles, directions and forces indicated.

\(\mu_K = F_K/F_N \\ a_y = 0\)

Correct.

What is the correct expression for the sum of the forces in the \(y\) direction?

(A)   \(F_N + F \sin \theta - mg = 0\)

(B)   \(F_N - F \sin \theta - mg = 0\)

(C)   \(F_N + F \sin \theta +mg = 0\)