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A particle moves move on the rough horiz...

A particle moves move on the rough horizontal ground with some initial velocity `V_(0)`. If `(3)/(4)` of its kinetic enegry lost due to friction in time `t_(0)`. The coefficient of friction between the particle and the ground is.

A

`(V_(0))/(2g t_(0))`

B

`(V_(0))/(4g t_(0))`

C

`(3V_(0))/(4g t_(0))`

D

`(V_(0))/(g t_(0))`

Text Solution

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The correct Answer is:
To solve the problem step by step, we need to analyze the given information about the particle's motion and the energy lost due to friction. ### Step 1: Understand the Initial Conditions The particle has an initial velocity \( V_0 \) and it loses \( \frac{3}{4} \) of its kinetic energy due to friction in time \( t_0 \). ### Step 2: Calculate Initial Kinetic Energy The initial kinetic energy (KE_initial) of the particle can be calculated using the formula: \[ KE_{\text{initial}} = \frac{1}{2} m V_0^2 \] ### Step 3: Determine Final Kinetic Energy Since the particle loses \( \frac{3}{4} \) of its kinetic energy, the final kinetic energy (KE_final) will be: \[ KE_{\text{final}} = KE_{\text{initial}} - \frac{3}{4} KE_{\text{initial}} = \frac{1}{4} KE_{\text{initial}} = \frac{1}{4} \left(\frac{1}{2} m V_0^2\right) = \frac{1}{8} m V_0^2 \] ### Step 4: Relate Final Kinetic Energy to Final Velocity The final kinetic energy can also be expressed in terms of the final velocity \( V_f \): \[ KE_{\text{final}} = \frac{1}{2} m V_f^2 \] Setting the two expressions for \( KE_{\text{final}} \) equal gives: \[ \frac{1}{8} m V_0^2 = \frac{1}{2} m V_f^2 \] Cancelling \( m \) from both sides and solving for \( V_f \): \[ \frac{1}{8} V_0^2 = \frac{1}{2} V_f^2 \implies V_f^2 = \frac{1}{4} V_0^2 \implies V_f = \frac{V_0}{2} \] ### Step 5: Apply the Equation of Motion Using the first equation of motion: \[ V_f = V_0 - a t_0 \] Where \( a \) is the retarding acceleration due to friction. The retarding force due to friction is given by: \[ F_{\text{friction}} = \mu m g \] Thus, the acceleration \( a \) is: \[ a = \frac{F_{\text{friction}}}{m} = \mu g \] Substituting this into the equation of motion gives: \[ \frac{V_0}{2} = V_0 - \mu g t_0 \] ### Step 6: Rearranging the Equation Rearranging the equation to solve for \( \mu \): \[ \mu g t_0 = V_0 - \frac{V_0}{2} = \frac{V_0}{2} \] \[ \mu = \frac{V_0}{2 g t_0} \] ### Final Answer The coefficient of friction \( \mu \) between the particle and the ground is: \[ \mu = \frac{V_0}{2 g t_0} \]

To solve the problem step by step, we need to analyze the given information about the particle's motion and the energy lost due to friction. ### Step 1: Understand the Initial Conditions The particle has an initial velocity \( V_0 \) and it loses \( \frac{3}{4} \) of its kinetic energy due to friction in time \( t_0 \). ### Step 2: Calculate Initial Kinetic Energy The initial kinetic energy (KE_initial) of the particle can be calculated using the formula: \[ ...
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A aprtical moves on a rough horizontal ground with same initial velocity say v_(0) . If (3//4)th of its kinetic energy is lost in friction in time t_(0) , then coefficient of friction between the partical and the ground is:

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Knowledge Check

  • A particle moves on a rough horizontal ground with some initial velocity say nu_(0) . If (3/4)th of its kinetic energy is lost in friction in time t_(0) , then coefficient of friction between the particle and the ground is:

    A
    `nu_(0)/(2"gt"_(0))`
    B
    `nu_(0)/(4"gt"_(0))`
    C
    `(3nu_(0))/(4"gt"_(0))`
    D
    `nu_(0)/"gt"_(0)`
  • A particle is projected directly along a rough plane of inclination theta with velocity u. If after coming to the rest the particle returns to the starting point with velocity v, the coefficient of friction between the partice and the plane is

    A
    `(u^(2))/(v^(2))tan theta`
    B
    `(u^(2)-v^(2))/(u^(2)+v^(2))tan theta`
    C
    `(v^(2))/(u^(2)) tan theta`
    D
    `(u^(2)+v^(2))/(u^(2)-v^(2)) tan theta`
  • Asseration : A block of mass m starts moving on a rough horizontal surface with a velocity v. It stops due to friction between the block and the surface after moving through a ceratin distance. The surface is now tilted to an angle of 30^@ with the horizontal and same block is made to go up on the surface with the same initial velocity v. The decrease in the mechanical energy in the second situation is small than the first situation. Reason : The coefficient of friction between the block and the surface decreases with the increase in the angle of inclination.

    A
    If both Assertion and Reason are true and the Reason is correct explanation of the Assertion.
    B
    If both Assertion and Reason are true and the Reason is not the correct explanation of the Assertion.
    C
    If Assertion is true, but the Reason is false
    D
    If Assertion is false but the Reason is true.
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