A 92 kg clock initially at rest on a horizontal floor requires a 656 N horizontal force to set it in motion. After the clock is in motion, a horizontal force of 560 N keeps it moving with a constant speed.
Wc = M*g = 92kg * 9.8N/kg = 902 N. =
wt. of the clock.
Fap-Fs = M*a
656 - Fs = M*0 = 0
Fs = 656 N. = Force of static friction.
us = Fap/Wc = 656/902 = 0.727
uk = 560/902 = 0.621
To find the coefficient of kinetic friction between the clock and the floor, we can use the formula:
μ = F_k / N
where μ is the coefficient of kinetic friction, F_k is the force of kinetic friction, and N is the normal force.
1. First, we need to find the normal force acting on the clock. Since the clock is on a horizontal floor and there is no vertical acceleration or vertical motion, the normal force is equal in magnitude and opposite in direction to the gravitational force acting on the clock.
N = mg
where m is the mass of the clock and g is the acceleration due to gravity.
N = (92 kg) * (9.8 m/s^2)
N = 901.6 N
2. Now, we can calculate the force of kinetic friction.
F_k = F_applied - F_net
where F_applied is the applied force to set the clock in motion and F_net is the net force acting on the clock when it is moving at a constant speed.
F_applied = 656 N
F_net = 560 N
F_k = F_applied - F_net
F_k = 656 N - 560 N
F_k = 96 N
3. Finally, we can calculate the coefficient of kinetic friction.
μ = F_k / N
μ = 96 N / 901.6 N
μ ≈ 0.1065
Therefore, the coefficient of kinetic friction between the clock and the floor is approximately 0.1065.