1. A man pulls a 300 N object across a horizontal surface using a 100 N force applied at a 35° angle. What is the normal force? If the object is pulled at constant speed, what is the coefficient of friction
I will be glad to critique your work.
To determine the normal force in this situation, we first need to understand what it is. The normal force is the force exerted perpendicular to a surface by an object in contact with it. In this case, the object is on a horizontal surface.
To find the normal force, we need to identify the components of the forces involved. The 100 N force applied by the man has two components: one in the horizontal direction and one in the vertical direction.
To find the vertical component of the force, we need to use trigonometry. The equation to calculate the vertical component (Fy) is:
Fy = F * sin(θ)
where F is the magnitude of the force (100 N) and θ is the angle at which it is applied (35°). Plugging in the values, we have:
Fy = 100 N * sin(35°)
Fy ≈ 57.09 N
Since the object is at rest on a horizontal surface, the normal force must be equal in magnitude but opposite in direction to the vertical component of the applied force. Therefore, the normal force is approximately 57.09 N, directed upward.
To find the coefficient of friction, we need to know the force of friction acting on the object. In this case, if the object is pulled at a constant speed, the force of friction must be equal in magnitude but opposite in direction to the applied force.
The equation to calculate the force of friction (Ff) is:
Ff = μ * N
where μ is the coefficient of friction and N is the normal force.
Given that the force of friction is equal to the applied force, we have:
Ff = 100 N
Substituting the known value for the normal force, we have:
100 N = μ * 57.09 N
To find μ, we divide both sides of the equation by 57.09 N:
μ = 100 N / 57.09 N
μ ≈ 1.75
Therefore, the coefficient of friction is approximately 1.75.