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A particle moves such that its momentum ...

A particle moves such that its momentum vector `vecp(t) = cos omega t hati + sin omega t hatj` where `omega` is a constant and t is time. Then which of the following statements is true for the velocity `vec v(t)` and acceleration `veca (t)` of the particle :

A

`vecV` is perpendicular to `vecP` and `veca` is directed towards the origin

B

`vec v` and `veca` both are parallel to `vecp`

C

`vecv` and `veca` both are perpendicular to `vecp`

D

`vecv` is parallel to `vecp` and `veca` is perpendicular to `vecp`

Text Solution

AI Generated Solution

The correct Answer is:
To solve the problem, we need to analyze the momentum vector given and derive the velocity and acceleration vectors from it. ### Step-by-Step Solution: 1. **Given Momentum Vector**: The momentum vector is given as: \[ \vec{p}(t) = \cos(\omega t) \hat{i} + \sin(\omega t) \hat{j} \] 2. **Relationship Between Momentum and Velocity**: The momentum \(\vec{p}\) is related to velocity \(\vec{v}\) by the equation: \[ \vec{p} = m \vec{v} \] where \(m\) is the mass of the particle. Thus, the velocity vector can be expressed as: \[ \vec{v}(t) = \frac{\vec{p}(t)}{m} = \frac{1}{m} \left( \cos(\omega t) \hat{i} + \sin(\omega t) \hat{j} \right) \] 3. **Finding the Acceleration Vector**: The acceleration \(\vec{a}\) is the time derivative of the velocity \(\vec{v}\): \[ \vec{a}(t) = \frac{d\vec{v}(t)}{dt} \] To differentiate \(\vec{v}(t)\): \[ \vec{a}(t) = \frac{1}{m} \left( -\omega \sin(\omega t) \hat{i} + \omega \cos(\omega t) \hat{j} \right) \] 4. **Analyzing the Direction of Velocity and Acceleration**: - The velocity vector \(\vec{v}(t)\) is in the direction of the momentum vector \(\vec{p}(t)\). - The acceleration vector \(\vec{a}(t)\) is derived from the velocity vector and involves sine and cosine terms, indicating a circular motion. 5. **Checking Perpendicularity**: To check if the velocity and acceleration vectors are perpendicular, we can take the dot product: \[ \vec{v}(t) \cdot \vec{a}(t) = \left( \frac{1}{m} \left( \cos(\omega t) \hat{i} + \sin(\omega t) \hat{j} \right) \right) \cdot \left( \frac{1}{m} \left( -\omega \sin(\omega t) \hat{i} + \omega \cos(\omega t) \hat{j} \right) \right) \] This simplifies to: \[ = \frac{\omega}{m^2} \left( \cos(\omega t)(\cos(\omega t)) + \sin(\omega t)(-\sin(\omega t)) \right) = \frac{\omega}{m^2} \left( \cos^2(\omega t) - \sin^2(\omega t) \right) \] This expression is not necessarily zero, indicating that \(\vec{v}(t)\) and \(\vec{a}(t)\) are not perpendicular. 6. **Conclusion**: - The velocity vector \(\vec{v}(t)\) is parallel to the momentum vector \(\vec{p}(t)\). - The acceleration vector \(\vec{a}(t)\) is perpendicular to the velocity vector \(\vec{v}(t)\). ### Final Answer: The correct statement is: - **Velocity is parallel to momentum, and acceleration is perpendicular to velocity.**

To solve the problem, we need to analyze the momentum vector given and derive the velocity and acceleration vectors from it. ### Step-by-Step Solution: 1. **Given Momentum Vector**: The momentum vector is given as: \[ \vec{p}(t) = \cos(\omega t) \hat{i} + \sin(\omega t) \hat{j} ...
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