WANTED: Formula for frictional resistance

In summary, the conversation discusses a question about the frictional resistance of a hydraulics lift using a specific formula. The lift consists of a ram and a cylinder filled with oil. The formula provided includes variables for velocity, coefficient of friction, and wetted surface. The conversation also mentions a website as a potential reference for the formula.
  • #1
clueless
I do remember you folks to like to see where I left things. Well, let's change the arrangement. Give me formula and I will do the rest.

A hydraulics lift (type commonly used for greasing automobile) consist of a 10.111-in-diameter ram that slides in a 10.006-in-diameter cylinder. The annual space being filled with oil having a kinematic viscocity of 0.0038 ft^2/sec and specific gravity of 0.83. If the rate of travel of the ram v is 0.5fps, find the frictional resistance, F when 6ft of the ram is engaged in the cylinder...

I think this is simply evaluating expression problem once the expression is known to me. Am I underestimating the question?
 
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  • #2
Is this what you are looking for?

Rf = 0.97 x Cf x Sw x V^2 where:

Rf = Resistance in pounds
Cf = Coefficient of friction
Sw = Wetted surface
V = Velocity in ft/sec
0.97 = Constant for fresh water

Source: http://www.greenval.com/shape_part1.html
 
  • #3
I am not sure whether I have the formula I was looking for because the fluid in my problem is oil not the water. I will check out the website you were referring to. Thanks for your time and kindness.
 

1. What is frictional resistance?

Frictional resistance is the force that opposes the motion of an object when it comes into contact with another object or surface.

2. Why is it important to have a formula for frictional resistance?

A formula for frictional resistance allows scientists and engineers to accurately calculate the amount of resistance an object will experience when moving against another surface. This information is crucial for designing efficient and effective machines and structures.

3. How is frictional resistance measured?

Frictional resistance is typically measured using a device called a tribometer. This instrument applies a known force to an object and measures the resulting frictional force.

4. What factors affect frictional resistance?

The amount of frictional resistance an object experiences is influenced by several factors, including the surface roughness of the objects in contact, the weight and surface area of the object, and the type of material the object is made of.

5. Can frictional resistance be reduced?

Yes, there are several ways to reduce frictional resistance, including using lubricants, polishing surfaces to reduce roughness, and using materials with low coefficients of friction. However, completely eliminating frictional resistance is not possible, as it is a natural force that occurs whenever two surfaces come into contact.

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