INCREASE in temperature of the material practically increase the energy of the particles. which increases their motion due to increase in energy . thus when the temperature is decreased the energy level decreases which causes the particle's motion to slow down.. the motion of the particle is highly reduced when the temperature is lowered
To solve this exercise it is necessary to take into account the concepts related to Tensile Strength and Shear Strenght.
In Materials Mechanics, generally the bodies under certain loads are subject to both Tensile and shear strenghts.
By definition we know that the tensile strength is defined as

Where,
Tensile strength
F = Tensile Force
A = Cross-sectional Area
In the other hand we have that the shear strength is defined as

where,
Shear strength
Shear Force
Parallel Area
PART A) Replacing with our values in the equation of tensile strenght, then

Resolving for F,

PART B) We need here to apply the shear strength equation, then



In such a way that the material is more resistant to tensile strength than shear force.
Answer:
49.63 degree
Explanation:
thickness of glass slab, t = 0.6 cm
angle of incidence = 59 degree
Let r be the angle of refraction
The refractive index of glass, ng = 3/2
refractive index of water, nw = 4/3
refarctive index of glass with respect to water = ng / nw = 3 /2 ÷ 4 /3 = 9 / 8
So, by use of Snell's law
Refractive index of glass with respect to water = Sin i / Sin r
9 / 8 = Sin 59 / Sin r
9 / 8 = 0.857 / Sin r
Sin r = 0.7619
r = 49.63 degree
Of course steady state condition occurs in almost any system but time it will occurs varies among system. for this kind of system, conduction, steady state conduction occurs when the temperature change from one point to the point is already constant. steady state is not achieved immediately because the heat travels and material will not be heated at the same way at the starting point.