solving simple material engineering problems

solve simple set of problems: if i found that you able to do so i will upload 1 every week 1. In a tension test with a 100 MPa applied stress a sample with initial 10 mm diameter and 50 mm length obtained a diameter of 9.90 mm and length of 51.02 mm. Calculate Poison’s ratio, elastic modulus and shear modulus, assuming all deformation is elastic: 2. Using a tape measure can result in errors depending on the material from which the tape measure was made. Assuming a 250 foot-long tape with width of 0.375 inches and thickness of 0.025 inches, calculate the error in measurement if the tape is pulled with a 20 lb force and the tape is made from: a. Steel (E = 30 x 106 psi) b. Aluminum (E = 10 x 106 psi) c. Fiberglass (E = 3.5 x 106 psi) 3. Steel with grain size 64 micrometers has strength of 600 MPa. The same steel with grain size 100 micrometers has strength of 550 MPa. What will be the strength of this steel if it has a grain size of 25 micrometers? (Hint: make a plot and use the special relationship between strength and grain size we talked about in class.) 4. Increasing the strength of a material by heat treatment is a good way to save weight (since you need less of a strong material), but there can be adverse consequences. Let’s say the tensile strength of a material is increased from 1475 MPa to 2140 MPa. With the increased strength, the fracture toughness is reduced from 58.5 to 23.3 MPa m1/2. Calculate the critical flaw size that will result in fracture if the part made from this material will be subject to a stress of 775 MPa. 5. The yield stress of a polycrystalline metal is almost always higher than that of a single crystal. Why?