Chapter 4, Problem 4.13P

1.  Does the area of contact affect the frictional force between the materials? Explain your answer. Please do not just copy from somewhere.

What happens or characteristics you observed when you change the copper wire material to aluminum and string? Make a distinction between the three materials.

For safe and reliable operation, a certain polypropylene pipe must withstand an internal pressure of 0.5 MPa for a minimum of three years. If the pipe diameter is 100 mm, what is the minimum necessary wall thickness to ensure that the pipe will not experience a strain greater than 1.3%? To solve this problem, use the accompanying graph that reveals the room temperature creep response for polypropylene.

Illustrate the shear stress vs shear strain relationship of the following materials: Ethanol, juice concentrate, Quick sand, blood, glycerin, ketchup and corn starch

What is Gorilla Glass from Corning? Why does it outperform regular window glass in terms of mechanical properties? Briefly explain utilizing basic mechanical principles. When necessary, provide diagrams to further explain your response.

Write typical values of E for diamond, steel, aluminum, silicate glass, polystyrene, and silicone rubber subjected to small strains (note that the latter value is not included in this chapter, but is widely available). Clearly indicate the units for each value.

A sample of cross-linked natural rubber (polyisoprene) is found to have a shear modulus of 100 kPa at 20˚C. Determine the force needed to stretch a 20 mm diameter by 100 mm long rod to 300 mm (stretched in the length direction). What is the diameter of this rod of natural rubber under such a load?

A cylindrical specimen of brass material 11mm in diameter and 110mm long is elastically deformed in tension with a force of 7853N which produces a 4.25x10^-3mm reduction in specimen diameter. Calculate the Poissons ratio for this material

Provide a concise explanation on how materials can exhibit high thermal conductivity but have low electrical conductivity.