Performing Metric Unit Conversions
2 answers:
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Hope it cleared your doubt.
Answer:
A) I_total = 16 m, B) I_total = 8 m, C) I_total = 8 m, D) I_total = 8 m
Explanation:
The moment of inertia is a scalar quantity, therefore the total moment of inertia
I_total = I₁ + I₂ + I₃ + I₄
the moment of inertia of a point mass with respect to an axis of rotation
I = m r²
Let's apply this to our case
A) Rotation axis at the origin
I₁ = m 0 = 0
for the second masses, we find the distance using the Pythagorean theorem
r =
r = 2 √2
I₂ = m (2 √2) ²
I₂ = 8 m
I₃ = m 2² = 4 m
I₄ = m 2² = 4 m
we substitute
I_total = 0 + 8m + 4m + 4m
I_total = 16 m
B) axis of rotation in the center of the square
let's find the distance to any mass
r =
r = √2
I₁ = m 2
I₂ = m 2
i₃ = m 3
I₄ = m 4
we substitute
I_total = 4 (2m)
I_total = 8 m
C) axis of rotation is the x axis
I₁ = 0
I₂ = m 2² = 4 m
I₃ = m 2² = 4 m
I₄ = 0
I_total = 8 m
D) axis of rotation is the y-axis
I₁ = 0
I₂ = 4m
I₃ = 0
I₄ = 4 m
I_total = 8 m