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STATEMENT-1: Radius of circular orbit of...

STATEMENT-1`:` Radius of circular orbit of a satellite is made two times, then its areal velocity will also becomes two times.
because
STATEMENT -2 `:` Areal velocity is given as `(dA)/( dt)= ( L)/( 2m)= ( mvr)/( 2m)`.

A

Statement-1 is True , Statement-2 is True, Statement-2 is a correct explanation for Statement-1.

B

Statement-1 is True , Statement-2 is True, Statement-2 is NOT a correct explanation for Statement-1.

C

Statement-1 is True, Statement-2 is False

D

Statement-1 is False, Statement-2 is True.

Text Solution

AI Generated Solution

The correct Answer is:
To solve the problem, we need to analyze the two statements provided and determine their validity based on the principles of physics related to circular motion and areal velocity. ### Step-by-Step Solution: 1. **Understanding Areal Velocity**: Areal velocity (dA/dt) is defined as the area swept out by the radius vector of a satellite in a given time. It can be expressed as: \[ \frac{dA}{dt} = \frac{L}{2m} \] where \(L\) is the angular momentum and \(m\) is the mass of the satellite. 2. **Expression for Angular Momentum**: The angular momentum \(L\) of a satellite in circular motion can be expressed as: \[ L = mvr \] where \(v\) is the orbital speed and \(r\) is the radius of the orbit. 3. **Substituting Angular Momentum into Areal Velocity**: Substituting the expression for \(L\) into the areal velocity equation gives: \[ \frac{dA}{dt} = \frac{mvr}{2m} = \frac{vr}{2} \] 4. **Relating Speed to Radius**: For a satellite in a circular orbit, the centripetal force is provided by gravitational force: \[ mg = \frac{mv^2}{r} \] From this, we can derive the speed \(v\): \[ v^2 = rg \quad \Rightarrow \quad v = \sqrt{rg} \] 5. **Substituting Speed into Areal Velocity**: Now substituting \(v\) into the areal velocity equation: \[ \frac{dA}{dt} = \frac{r \sqrt{rg}}{2} = \frac{r^{3/2}g^{1/2}}{2} \] 6. **Effect of Doubling the Radius**: If the radius \(r\) is doubled (i.e., \(r' = 2r\)): \[ \frac{dA'}{dt} = \frac{(2r)^{3/2}g^{1/2}}{2} = \frac{2^{3/2}r^{3/2}g^{1/2}}{2} = \frac{2\sqrt{2}r^{3/2}g^{1/2}}{2} = \sqrt{2} \cdot r^{3/2}g^{1/2} \] This shows that the new areal velocity is not simply double the original areal velocity, but rather it is multiplied by \(\sqrt{2}\). 7. **Conclusion**: Therefore, **Statement 1** is false because the areal velocity does not become two times when the radius is doubled; it actually becomes \(\sqrt{2}\) times the original value. **Statement 2** is true as it correctly describes the relationship between areal velocity and angular momentum. ### Final Answer: - **Statement 1** is false. - **Statement 2** is true. - The correct option is **D**: Statement 1 is false and Statement 2 is true.
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