Which of the following statements about physical models is not true?
a.
physical models are often three-dimensional representations.
b.
physical models are used to represent an object or event.
c.
physical models are usually in the form of a graph.
d.
physical models can be used to depict microscopic objects.

Determine the change in width a, height b, thickness t when a plate is subjected to the uniform distributed load and is made of material having modulus of elasticity e=230 gpa and poisson's ratio ν=1/3. given : a=400 mm and b= 300 mm also the uniformly distributed load in downward y direction of plate is 2 mn/m and in the positive x direction is 3 mn/m and t=20 mm