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The time period of a compound pendulum i...

The time period of a compound pendulum is given by
`T=2pisqrt((I)/(mgl))`
`{:(,"where","I=moment of inertia about the centre of the suspension,"),(,,"g=acceleration due to gravity , m=mass of the pendulam"),(,,"l=distance of the centre of the gravity from the centre of the suspension."):}`

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To verify the dimensional correctness of the formula for the time period of a compound pendulum, we will follow these steps: ### Step 1: Identify the formula The formula for the time period \( T \) of a compound pendulum is given by: \[ T = 2\pi \sqrt{\frac{I}{mgl}} \] where: - \( I \) = moment of inertia about the center of suspension - \( m \) = mass of the pendulum - \( g \) = acceleration due to gravity - \( l \) = distance from the center of gravity to the center of suspension ### Step 2: Determine the dimensions of the left-hand side (LHS) The left-hand side of the equation is the time period \( T \). The dimension of time \( T \) is: \[ [T] = [M^0 L^0 T^1] \] ### Step 3: Determine the dimensions of the right-hand side (RHS) The right-hand side involves the expression \( \sqrt{\frac{I}{mgl}} \). We need to find the dimensions of \( I \), \( m \), \( g \), and \( l \). 1. **Moment of Inertia \( I \)**: The moment of inertia for a point mass is given by \( I = mr^2 \). Thus, its dimension is: \[ [I] = [M^1 L^2 T^0] \] 2. **Mass \( m \)**: The dimension of mass is: \[ [m] = [M^1 L^0 T^0] \] 3. **Acceleration due to gravity \( g \)**: The dimension of acceleration is: \[ [g] = [M^0 L^1 T^{-2}] \] 4. **Distance \( l \)**: The dimension of distance is: \[ [l] = [M^0 L^1 T^0] \] ### Step 4: Combine the dimensions in the RHS expression Now we can substitute these dimensions into the RHS: \[ \frac{I}{mgl} = \frac{[M^1 L^2 T^0]}{[M^1][M^0 L^1 T^{-2}][M^0 L^1]} \] This simplifies to: \[ \frac{[M^1 L^2 T^0]}{[M^1 L^2 T^{-2}]} = [M^0 L^0 T^2] \] ### Step 5: Take the square root Now, we take the square root of the result: \[ \sqrt{[M^0 L^0 T^2]} = [M^0 L^0 T^1] \] ### Step 6: Multiply by \( 2\pi \) Since \( 2\pi \) is a dimensionless constant, it does not affect the dimensions: \[ T = 2\pi \sqrt{\frac{I}{mgl}} \implies [T] = [M^0 L^0 T^1] \] ### Step 7: Compare LHS and RHS Now we compare the dimensions of LHS and RHS: - LHS: \( [M^0 L^0 T^1] \) - RHS: \( [M^0 L^0 T^1] \) Since both sides are equal, the formula is dimensionally correct. ### Conclusion The formula for the time period of a compound pendulum is dimensionally correct. ---
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