Given below are two statements, one is labelled as Assertion A and the other is labelled as Reason R
Assertion (A) : A person standing on a rotating platform suddenly stretched his arms. The platform slows down.
Reason (R) : This happens as angular momentum is conserved.
In the light of the above statements, choose the correct answer from the options given below
Given below are two statements, one is labelled as Assertion A and the other is labelled as Reason R
Assertion (A) : A person standing on a rotating platform suddenly stretched his arms. The platform slows down.
Reason (R) : This happens as angular momentum is conserved.
In the light of the above statements, choose the correct answer from the options given below
- If both assertion and reason are true and reason is the correct explanation of assertion
- If both assertion and reason are true but reason is not the correct explanation of assertion
- If assertion is true but reason is false
- If both assertion and reason are false
The Correct Option is A
Solution and Explanation
Answer (a) If both assertion and reason are true and reason is the correct explanation of assertion
Assertion (A) : A person standing on a rotating platform suddenly stretched his arms. The platform slows down. (correct)
Reason (R) : This happens as angular momentum is conserved. (True and correct explanation)
Top Questions on Moment Of Inertia
A circular disc has radius \( R_1 \) and thickness \( T_1 \). Another circular disc made of the same material has radius \( R_2 \) and thickness \( T_2 \). If the moments of inertia of both the discs are same and \[ \frac{R_1}{R_2} = 2, \quad \text{then} \quad \frac{T_1}{T_2} = \frac{1}{\alpha}. \] The value of \( \alpha \) is __________.
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Concepts Used:
Moment of Inertia
Moment of inertia is defined as the quantity expressed by the body resisting angular acceleration which is the sum of the product of the mass of every particle with its square of a distance from the axis of rotation.
Moment of inertia mainly depends on the following three factors:
- The density of the material
- Shape and size of the body
- Axis of rotation
Formula:
In general form, the moment of inertia can be expressed as,
I = m × r²
Where,
I = Moment of inertia.
m = sum of the product of the mass.
r = distance from the axis of the rotation.
M¹ L² T° is the dimensional formula of the moment of inertia.
The equation for moment of inertia is given by,
I = I = ∑mi ri²
Methods to calculate Moment of Inertia:
To calculate the moment of inertia, we use two important theorems-
- Perpendicular axis theorem
- Parallel axis theorem