Class 11 Exam  >  Class 11 Questions  >  A rigid body can be hinged about any point on... Start Learning for Free
A rigid body can be hinged about any point on the x-axis. When it is hinged such that the hinge is at x, the moment of inertia is given by
I = 2x2 - 12x + 27 The x-coordinate of centre of mass is
  • a)
     x = 2 
  • b)
    x = 0
  • c)
    x = 1
  • d)
    x = 3
Correct answer is option 'D'. Can you explain this answer?
Most Upvoted Answer
A rigid body can be hinged about any point on the x-axis. When it is h...
Moment of inertia is minimum at centre of mass of the body.
I=minimum for centre of mass

Therefore x co-ordinate of centre of mass is 3 unit. 

Free Test
Community Answer
A rigid body can be hinged about any point on the x-axis. When it is h...
Given:
Moment of Inertia, I = 2x^2 - 12x + 27
We need to find the x-coordinate of the Centre of Mass.

Formula:
Centre of Mass, Xcm = (Σmixi) / Σmi

Approach:
We need to find the mass distribution function for the given moment of inertia function.

Derivation for mass distribution function:
I = ∫r^2 dm
where 'r' is the distance from the axis of rotation and 'dm' is the mass element

let's consider a small element of mass 'dm' at a distance 'x' from the origin
I = ∫ r^2 dm = ∫ x^2 dm

Consider a small element of length 'dx' containing mass 'dm'
dm = λdx
where 'λ' is the linear mass density of the element
λ = m/L
where 'm' is the mass of the object and 'L' is the total length of the object

dm = (m/L)dx

r = x
I = ∫ x^2 dm = ∫ x^2 (m/L)dx = (m/L) ∫ x^2 dx
I = (m/L) [x^3/3]

m/L = 3I / x^3

Substitute this value in the dm equation
dm = (3I / x^3) dx

Now, we can find the total mass of the object by integrating the mass distribution function
M = ∫ dm = ∫ (3I / x^3) dx
M = 3I ∫ x^-3 dx
M = -3I [x^-2/2]

M = (3/2) I (1/x^2)

We can find the x-coordinate of the Centre of Mass using the formula mentioned above.

Calculation:
Σmi = (3/2) I (1/x^2) * x
Σmi = (3/2) I (1/x)
Σmi = (3/2) (2x^2 - 12x + 27) / x
Σmi = (3/2) (2x - 12 + 27/x)

Σmi = (3/2) [2(x-3) + 33/x]

Σmi = 3(x-3) + (99/x)

Σmi = (3x - 6 + 99) / x

Σmi = (3x + 93) / x

Xcm = (Σmixi) / Σmi
Xcm = [(3/2) I (1/x^2) * x^2] / [(3x + 93) / x]
Xcm = (3/2) I / (3x + 93)

Substitute the given value of I in the above equation
Xcm = (3/2) (2x^2 - 12x + 27) / (3x + 93)
Xcm = (3/2) [(2x-3) / (x+31)]

Xcm = 3(x-3) / (2x+62)

Hence, the x-coordinate of the Centre of Mass is x = 3.
Explore Courses for Class 11 exam

Top Courses for Class 11

Question Description
A rigid body can be hinged about any point on the x-axis. When it is hinged such that the hinge is at x, the moment of inertia is given byI = 2x2-12x + 27 The x-coordinate of centre of mass isa)x = 2b)x = 0c)x = 1d)x = 3Correct answer is option 'D'. Can you explain this answer? for Class 11 2025 is part of Class 11 preparation. The Question and answers have been prepared according to the Class 11 exam syllabus. Information about A rigid body can be hinged about any point on the x-axis. When it is hinged such that the hinge is at x, the moment of inertia is given byI = 2x2-12x + 27 The x-coordinate of centre of mass isa)x = 2b)x = 0c)x = 1d)x = 3Correct answer is option 'D'. Can you explain this answer? covers all topics & solutions for Class 11 2025 Exam. Find important definitions, questions, meanings, examples, exercises and tests below for A rigid body can be hinged about any point on the x-axis. When it is hinged such that the hinge is at x, the moment of inertia is given byI = 2x2-12x + 27 The x-coordinate of centre of mass isa)x = 2b)x = 0c)x = 1d)x = 3Correct answer is option 'D'. Can you explain this answer?.
Solutions for A rigid body can be hinged about any point on the x-axis. When it is hinged such that the hinge is at x, the moment of inertia is given byI = 2x2-12x + 27 The x-coordinate of centre of mass isa)x = 2b)x = 0c)x = 1d)x = 3Correct answer is option 'D'. Can you explain this answer? in English & in Hindi are available as part of our courses for Class 11. Download more important topics, notes, lectures and mock test series for Class 11 Exam by signing up for free.
Here you can find the meaning of A rigid body can be hinged about any point on the x-axis. When it is hinged such that the hinge is at x, the moment of inertia is given byI = 2x2-12x + 27 The x-coordinate of centre of mass isa)x = 2b)x = 0c)x = 1d)x = 3Correct answer is option 'D'. Can you explain this answer? defined & explained in the simplest way possible. Besides giving the explanation of A rigid body can be hinged about any point on the x-axis. When it is hinged such that the hinge is at x, the moment of inertia is given byI = 2x2-12x + 27 The x-coordinate of centre of mass isa)x = 2b)x = 0c)x = 1d)x = 3Correct answer is option 'D'. Can you explain this answer?, a detailed solution for A rigid body can be hinged about any point on the x-axis. When it is hinged such that the hinge is at x, the moment of inertia is given byI = 2x2-12x + 27 The x-coordinate of centre of mass isa)x = 2b)x = 0c)x = 1d)x = 3Correct answer is option 'D'. Can you explain this answer? has been provided alongside types of A rigid body can be hinged about any point on the x-axis. When it is hinged such that the hinge is at x, the moment of inertia is given byI = 2x2-12x + 27 The x-coordinate of centre of mass isa)x = 2b)x = 0c)x = 1d)x = 3Correct answer is option 'D'. Can you explain this answer? theory, EduRev gives you an ample number of questions to practice A rigid body can be hinged about any point on the x-axis. When it is hinged such that the hinge is at x, the moment of inertia is given byI = 2x2-12x + 27 The x-coordinate of centre of mass isa)x = 2b)x = 0c)x = 1d)x = 3Correct answer is option 'D'. Can you explain this answer? tests, examples and also practice Class 11 tests.
Explore Courses for Class 11 exam

Top Courses for Class 11

Explore Courses
Signup for Free!
Signup to see your scores go up within 7 days! Learn & Practice with 1000+ FREE Notes, Videos & Tests.
10M+ students study on EduRev