# Young’s modulus of the brick

Young's modulus of the brick

A brick of length 215mm, width 102.5mm and height of 65mm is stepped on by a man weighing 800N. The Young’s modulus of the brick is 20,000MN/m2. What is the strain on the brick!
I really can’t figure how to calculate this one

It has to be in the linear region because the material is brittle. Is there a picture that goes with this? how is the man standing on the brick? (uniformly distributed load?). If this is the case, calculate the area of the brick that he is standing on in “meters”. Then divided the weight by the area to get N/m^2. Then use the relationship of strain=youngs modulus per sq. meter / stress sq. meter

I believe first to correctly use Young’s modulus you are assuming that the brick is in the linear region of the stress strain curve-otherwise the simple stress equation won’t apply. I think that you will have to look this one up because it will have strain in all 3 planes. To answer what the strain is you might need Poisson’s ratio if I remember correctly. Finally, I think you must also ask if the brick is constrained in any other directions(besides vertically) because this will affect your deformation equations also. As a check you should have 3 solutions where each is a directional strain(x,y,z), and assuming that the brick isn’t constrained in any way 2 should be positive and the vertical direction negative or compressive.

Youngs Modulus = stress/strain
stress = force/area

strain = stress/youngs modulus

hope that helps