Question

As stated in the introduction, shear strength is another measure of the strength of a material. A shear force is a force that acts parallel to the plane in the material that breaks. A good example of a shear is that of a martial arts expert breaking boards or bricks with her hands. Other applications in which shear forces and shear strength need to be known are geology, for studying earthquakes and landslides; fluid dynamics; and structural engineering. Aluminum has a shear strength of 210 megapascals. When you bend aluminum foil around an edge (i.e., the edge of the box) and pull, you are effectively applying a shear force along the bent edge of the foil. If a roll of household aluminum foil is 30.0 centimeters wide and its thickness is approximately 15.0 micrometers, how much shear force is needed to pull off a sheet?

Answer 1

`F=945\ N`

Step-by-step explanation:

Given:

• shear stress strength of the aluminium,
  `\tau=210\ MPa`

• width of aluminium foil,
  `w=300\ mm`

• thickness of aluminium foil,
  `t=15* 10^(-3)\ mm`

We know the relation between shear force and shear stress as:

`\tau=(F)/(A)`

where:

`A =` area subjected to the force F

Here the area subjected under the shear force is the bent part of the aluminium foil whole along the width.

`210=(F)/(15* 10^(-3) * 300)}`

`F=945\ N`