Question

Given that the tensile strength of aluminum foil is 311 megapascals, its thickness is approximately 15.0 micrometers, and a roll of household aluminum foil is 30.0 centimeters wide, how much force f is needed to pull off a sheet to use? assume that the force is applied equally along the whole width of the foil, and that you are trying to pull perpendicular to the cross section.

Answer 1

We need to know the area of the cross section of the sample before anything else. In this case, the aluminum sample has a width of 30.00 centimeters and a thickness of 15.0 micrometers,

Area = .30 x .000015 = 4.5 x 10^-6 m^2

the tensile strength to be 311 MPa so,

311x10^6 = F / 4.5 x 10^-6 m^2

F = 1399.5 N is needed

Hope this answers the question.