A block of mass m is placed at the distance of 1m from the centre of a...
There will be net force due to both the radial and tangential acceleration,
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A block of mass m is placed at the distance of 1m from the centre of a...
Given data:
- Mass of block (m) = ?
- Distance from center of turn table (r) = 1m
- Angular acceleration of turn table (α) = 3 rad/s^2
- Coefficient of friction (μ) = 0.5
Approach:
- We need to find the time at which the block is just about to slip on the turn table.
- To do this, we will calculate the maximum angular velocity the turn table can reach before the block slips.
- Then we will use the relation between angular velocity and time to find the required time.
Calculation:
- The maximum angular velocity the turn table can reach without the block slipping can be found using the equation of motion for rotational motion:
$\tau = Iα$
where $\tau$ is the torque due to friction, I is the moment of inertia of the turn table, and α is the angular acceleration.
- The torque due to friction can be calculated as:
$\tau = μmgd$
where μ is the coefficient of friction, m is the mass of the block, g is the acceleration due to gravity, and d is the distance between the block and the center of the turn table.
- Equating the two equations, we get:
$μmgd = Iα$
- Substituting the values, we get:
$0.5 * m * 9.8 * 1 = (1/2) * m * 1^2 * 3$
Solving this, we get: m = 3.27 kg
- Now, we can find the angular velocity at which the block is just about to slip:
$ω = ω_0 + αt$
where $ω_0$ is the initial angular velocity of the turn table.
- At time t = x/3 sec, the block is just about to slip, so the angular velocity of the turn table at this time will be the maximum angular velocity without slipping.
- Solving for x, we get:
$3x/3 = ω_0 + 3 * x/3$
$x = 2$
Therefore, the value of x is 2.
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