I have a few questions.
1.The coefficient of sliding friction between steel skate blades and ice is .05. How much force must be applied to a 150lb. skater to maintain a constant velocity?
2. If it takes a force of 6 pounds to cause a 24 pound box to slide on a level surface, what is the value of the static friction?
3.If the coefficient of kinetic friction is 75% of the coefficient of static friction, how much force is needed to keep the box in problem 2 moving at a constant velocity?
1. The product of the two numbers is the required force.
2. 6/24 = static friction coefficient
3. 75% of previous answer x (24 lb)= ?
Sure! I can help you with your questions. Let's go through them one by one:
Question 1:
To find the force required to maintain a constant velocity, we can use the equation:
Force of friction = coefficient of sliding friction * normal force
where the normal force is the weight of the skater.
Given:
Coefficient of sliding friction (μ) = 0.05
Weight of the skater = 150 lb
First, we need to convert the weight of the skater from pounds to Newtons (since force is typically measured in Newtons).
1 lb ≈ 4.45 N
Weight of the skater = 150 lb * 4.45 N/lb
Now we can calculate the force of friction:
Force of friction = 0.05 * (Weight of the skater)
Question 2:
To find the value of static friction, we can use the equation:
Force of friction = static friction = coefficient of static friction * normal force
Given:
Force to cause sliding = 6 lb
Weight of the box = 24 lb
First, we again need to convert the weight of the box from pounds to Newtons.
Weight of the box = 24 lb * 4.45 N/lb
Now we can find the value of static friction:
Force of friction = static friction = coefficient of static friction * (Weight of the box)
Question 3:
To find the force needed to keep the box moving at a constant velocity, we again use the equation:
Force of friction = kinetic friction = coefficient of kinetic friction * normal force
Given:
Coefficient of kinetic friction = 0.75 * coefficient of static friction
Weight of the box (from problem 2)
First, we already know the value of the static friction from problem 2.
Now we can find the value of kinetic friction:
Force of friction = kinetic friction = 0.75 * (static friction)
I hope this helps! Let me know if you need any further clarification.
Sure! I can help you with your questions. Let's go through each question step by step.
1. To determine the force required to maintain a constant velocity, we need to use the equation for sliding friction:
F_friction = coefficient * normal force
The normal force on the skater can be calculated using the weight of the skater:
Normal force = weight = mass * gravity
Given that the skater weighs 150 lbs, we need to convert it to mass using the conversion factor of 1 lb = 0.45359 kg.
Mass = 150 lbs * 0.45359 kg/lb
Once we have the mass, we can calculate the normal force:
Normal force = mass * gravity
where gravity is approximately 9.8 m/s^2.
Now we have all the values we need to calculate the force of friction:
F_friction = coefficient * normal force
Plugging in the values:
F_friction = 0.05 * (mass * gravity)
This will give you the force required to maintain a constant velocity.
2. The force required to overcome static friction and start an object in motion is equal to the maximum value of static friction. In this case, the given force is 6 pounds.
The value of the static friction can be calculated as:
Static friction = force
Therefore, the value of static friction in this case is 6 pounds.
3. The force required to keep the box in motion at a constant velocity is equal to the kinetic friction.
We are given that the coefficient of kinetic friction is 75% of the coefficient of static friction. Let's denote the coefficient of static friction as μ_s and the coefficient of kinetic friction as μ_k.
μ_k = 0.75 * μ_s
We already know that the force required to overcome static friction is 6 pounds. Let's denote this force as F_static.
F_static = static friction = μ_s * normal force
Now, we can calculate the kinetic friction force using the relationship between kinetic and static friction:
F_kinetic = μ_k * normal force
But we already know that μ_k = 0.75 * μ_s, so we can substitute that in:
F_kinetic = (0.75 * μ_s) * normal force
Therefore, the force needed to keep the box moving at a constant velocity is given by F_kinetic.
I hope this helps! Let me know if you have any further questions.