If the coefficient of kinetic friction is 0.25 , how much horizontal force is needed to pull each of the following masses along a rough desk at a constant speed?
A) 25 kg
Wm = mg = 25kg * 9.8m/kg = 245 N. = Wt.
of the mass.
Fm = 245N @ 0 Deg. = Forc of te mas.
Fp = 245*sin(0) = 0 = Force parallel to
desk.
Fv = 245*cos(0) = 245 N. = Force Perpendicular to the desk.
Fn = Fap -Fp - Fk = ma. a = 0.
Fap -0 - 0.25*245 = 25*0 = 0.
Fap - 61.25 = 0.
Fap = 61.25 N. = Force applied = Force
to move mass.
To determine the horizontal force needed to pull an object along a rough surface at a constant speed, we need to consider the coefficient of kinetic friction and the weight of the object.
The formula to calculate the force of kinetic friction is:
Friction Force = coefficient of kinetic friction x Normal Force
The Normal Force can be calculated as the weight of the object, which is equal to the mass of the object multiplied by the acceleration due to gravity (9.8 m/s^2).
1) Calculating the Normal Force:
Given mass (m) = 25 kg
Acceleration due to gravity (g) = 9.8 m/s^2
Normal Force (N) = mass x acceleration due to gravity
N = 25 kg x 9.8 m/s^2
N = 245 N
2) Calculating the Friction Force:
Given coefficient of kinetic friction (μ) = 0.25
Friction Force = μ x Normal Force
Friction Force = 0.25 x 245 N
Friction Force = 61.25 N
Therefore, a horizontal force of 61.25 N is needed to pull a 25 kg mass along a rough desk at a constant speed.