Respuesta :
Answer:
Explanation:
To get the person Moving you have to overcome the static (means not moving) friction coefficient. U(static)
To get the person going at the same speed you have to overcome the kinetic friction coefficient. U(Kinetic)
Force to get him moving is 198 N. Force = ma = U(static)Mg
combining the 2 equations you get 198N = U(static)* 55kg *9.8m/s^2 Solve for U(static)
Same equation to keep him moving except with the dynamic force and the dynamic U
175N= U(kinetic)*55kg*9.8m/s^2 Solve (U dynamic)
Newton's second law and the expression of the friction force allow to find the result for the value of the kinetic friction coefficient is:
μ = 0.325
Newton's second law establishes a relationship between the net force, mass, and acceleration of the body.
Σ F = m a
Where the bold letters indicate vectors, m is the mass and the acceleration.
The friction force is a macroscopic force that represents the interactions between the two surfaces, it can be of two types:
- Static. If there is no relative movement between the two surfaces.
- Kinetics. If there is relative movement between the two surfaces.
The expression in both cases is:
fr = μ N
Where N is the normal and μ is the friction coefficient, one value for the static case and another for the kinetic case.
In the attachment we have a free-body diagram for when the skater is moving with constant speed.
y=axis
N - W = 0
N = W
x-axis
F - fr = 0
F = fr
They indicate that the applied force is F = 175N and the mass of the skater is m = 55 kg.
We substitute.
F = μ mg
μ = [tex]\frac{F}{mg}[/tex]
Let's calculate.
μ =[tex]\frac{175}{55 \ 9.8}[/tex] 175/55 9.8
μ = 0.32
In conclusion, using Newton's second law and the expression of the friction force we can find the result for the value of the coefficient of kinetic friction is:
μ = 0.325
Learn more here: brainly.com/question/1714663
