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A force barF=barVxxbarA is exerted on a...

A force `barF=barVxxbarA` is exerted on a particle in addition to the force of gravity, where `barV` is the velocity of the particle and `barA` is a constant vector in the horizontal direction. The minimum speed of a particle of mass 3kg be projected, so that it continues to move undeflected with a constant velocity is `(xg)/A.` Then 'x' is (consider the plane of the ground as xy plane)

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To solve the problem, we need to analyze the forces acting on the particle and derive the minimum speed required for it to move undeflected with constant velocity. ### Step-by-Step Solution: 1. **Identify the Forces Acting on the Particle:** - The gravitational force acting downward on the particle is given by \( \bar{F}_g = m\bar{g} \), where \( m = 3 \, \text{kg} \) is the mass of the particle and \( \bar{g} \) is the acceleration due to gravity. - An additional force \( \bar{F} = \bar{V} \times \bar{A} \) is acting on the particle, where \( \bar{V} \) is the velocity of the particle and \( \bar{A} \) is a constant vector in the horizontal direction. 2. **Set Up the Equation for Constant Velocity:** - For the particle to move with constant velocity, the net force acting on it must be zero. This means that the upward component of the force \( \bar{F} \) must balance the downward gravitational force \( \bar{F}_g \). - The upward component of the force can be expressed as \( F_{\text{up}} = |\bar{V}| |\bar{A}| \sin \theta \), where \( \theta \) is the angle between the velocity vector \( \bar{V} \) and the vector \( \bar{A} \). 3. **Equate the Forces:** - Since the net force is zero, we can write: \[ |\bar{V}| |\bar{A}| \sin \theta = mg \] - Rearranging gives us: \[ |\bar{V}| = \frac{mg}{|\bar{A}| \sin \theta} \] 4. **Determine Minimum Speed:** - To find the minimum speed \( |\bar{V}| \), we need to maximize \( \sin \theta \). The maximum value of \( \sin \theta \) is 1 (when \( \theta = 90^\circ \)). - Thus, the minimum speed becomes: \[ |\bar{V}|_{\text{min}} = \frac{mg}{|\bar{A}|} \] 5. **Substitute Known Values:** - Given \( m = 3 \, \text{kg} \) and substituting \( g \) (approximately \( 9.81 \, \text{m/s}^2 \)): \[ |\bar{V}|_{\text{min}} = \frac{3 \times 9.81}{|\bar{A}|} = \frac{29.43}{|\bar{A}|} \] 6. **Compare with Given Expression:** - The problem states that the minimum speed is given by \( \frac{xg}{A} \). - We can equate this with our derived expression: \[ \frac{29.43}{|\bar{A}|} = \frac{xg}{A} \] - Since \( g \) is a constant, we can compare coefficients: \[ x = 3 \] ### Final Answer: Thus, the value of \( x \) is \( 3 \). ---
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