A long thin rod lies along the x-axis from the origin to x=L, with L= 0.890 m. The mass per unit length, λ (in kg/m) varies according to the equation λ = λ0 (1+1.410x2). The value of λ0 is 0.700 kg/m and x is in meters.

1. Calculate the total mass of the rod.
2. Calculate the x-coordinate of the center of mass of the rod.
3. Calculate the moment of inertia of the rod with respect to the y-axis.

User Icon for Explain Bot Explain Bot answered
1 year ago

1. To calculate the total mass of the rod, we need to integrate the mass density over the length of the rod.

The mass per unit length, λ, is given by λ = λ0 (1 + 1.410x^2), where λ0 = 0.700 kg/m.

To find the total mass, we integrate λ over the length of the rod from x = 0 to x = L:

M = ∫λ dx

M = ∫(λ0 (1 + 1.410x^2)) dx

M = λ0 ∫(1 + 1.410x^2) dx

M = λ0 [x + (1.410/3)x^3] evaluated from x = 0 to x = L

M = λ0 (L + (1.410/3)L^3)

Substituting the given values, L = 0.890 m and λ0 = 0.700 kg/m, we can calculate the total mass.

2. To calculate the x-coordinate of the center of mass of the rod, we need to find the mean position of the mass along the x-axis.

The x-coordinate of the center of mass, x_cm, is given by

x_cm = ∫(λx) dx / M

x_cm = ∫(λ0 (1 + 1.410x^2)x) dx / M

x_cm = λ0/M ∫(x + 1.410x^3) dx

x_cm = λ0/M [(1/2)x^2 + (1.410/4)x^4] evaluated from x = 0 to x = L

x_cm = λ0/M [(1/2)L^2 + (1.410/4)L^4]

Substituting the given values, L = 0.890 m and λ0 = 0.700 kg/m, and the calculated value of M from part 1, we can calculate the x-coordinate of the center of mass.

3. To calculate the moment of inertia of the rod with respect to the y-axis, we need to integrate the squared distance of each small mass element from the y-axis.

The moment of inertia, I, is given by

I = ∫(λx^2) dx

I = ∫(λ0 (1 + 1.410x^2)x^2) dx

I = ∫(λ0 (x^2 + 1.410x^4)) dx

I = λ0 ∫(x^2 + 1.410x^4) dx

I = λ0 [(1/3)x^3 + (1.410/5)x^5] evaluated from x = 0 to x = L

I = λ0 [(1/3)L^3 + (1.410/5)L^5]

Substituting the given values, L = 0.890 m and λ0 = 0.700 kg/m, we can calculate the moment of inertia.