Consider the following statements Modulus of rigidity and bulk modulu...
G = 60 GPa
K = 140 GPa
μ = 0.31 ≈ 0.3 Statement 2 and 3 are correct.
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Consider the following statements Modulus of rigidity and bulk modulu...
To determine the correct statements, let's review the definitions and relationships between the different elastic moduli.
1. Modulus of Rigidity (Shear Modulus): The modulus of rigidity, also known as the shear modulus, measures the resistance of a material to shearing deformation. It is denoted by G and has units of pressure (Pa or N/m²). In this case, the modulus of rigidity is given as 60 GPa (GigaPascals).
2. Bulk Modulus: The bulk modulus measures the resistance of a material to uniform compression or volume change. It is denoted by K and also has units of pressure (Pa or N/m²). In this case, the bulk modulus is given as 140 GPa.
3. Young's Modulus (Elasticity Modulus): Young's modulus, also known as the elasticity modulus, measures the stiffness of a material and its ability to resist linear elastic deformation. It is denoted by E and has units of pressure (Pa or N/m²). Young's modulus can be related to the modulus of rigidity and bulk modulus through the following equations:
Young's modulus (E) = 2 x Modulus of Rigidity (G) x (1 + Poisson's ratio)
Bulk modulus (K) = Young's modulus (E) / (3 x (1 - 2 x Poisson's ratio))
To determine the correct statements, we can use the given values of the modulus of rigidity and bulk modulus and solve for the other parameters.
Let's evaluate each statement:
1. Elasticity modulus is nearly 200 GPa:
Using the equation above, we can rearrange it to solve for Young's modulus (E):
E = 2 x G x (1 + Poisson's ratio)
E = 2 x 60 GPa x (1 + Poisson's ratio)
We don't have the value of Poisson's ratio, so we cannot determine the exact value of Young's modulus. Therefore, statement 1 is incorrect.
2. Poisson's ratio is nearly 0.3:
Since we don't have the value of Poisson's ratio, we cannot determine whether it is approximately 0.3 or not. Therefore, statement 2 is incorrect.
3. Elasticity modulus is nearly 158 GPa:
Using the equation above, we can rearrange it to solve for Young's modulus (E):
E = 2 x G x (1 + Poisson's ratio)
E = 2 x 60 GPa x (1 + Poisson's ratio)
Again, without the value of Poisson's ratio, we cannot determine the exact value of Young's modulus. Therefore, statement 3 is incorrect.
4. Poisson's ratio is nearly 0.25:
Using the equation for the bulk modulus, we can rearrange it to solve for Poisson's ratio:
Poisson's ratio = (1 - (E / (3 x K))) / 2
Substituting the given values, we have:
Poisson's ratio = (1 - (E / (3 x 140 GPa))) / 2
Without knowing the value of Young's modulus, we cannot calculate the exact value of Poisson's ratio. However, we can see that the value of Poisson's ratio will be less than 0.5 since the numerator of the equation is always positive. Therefore,
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