At a speed of 60 mph, how far does your car travel in 3 seconds
1 answer:
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Answer:
Explanation:
radius of hoop and the radius of disk is same = R
Let the mass of hoop is M and the mass of disk is M'.
As they reach the bottom of teh surface in same time so they travel equal distance thus, they have same acceleration.
The acceleration is given by
As the acceleration is same so that the moment of inertia is also same.
Moment of inertia of disk = moment of inertia of hoop
1/2 x mass of disk x R² = mass of hoop x R²
So, mass of disk = 2 x mass of hoop
Option (c) is correct.
Answer:
Explanation:
The capacitance of a parallel-plate capacitor is given by
where is the vacuum permittivity, A is the surface area of the plates, d their separation.
We also know the following relationship
where Q is the charge stored on the capacitor and V the potential difference between the plates.
Combining the two equations,
We also know that for a uniform electric field (such as the one between the plates of a parallel-plate capacitor), we have
where E is the magnitude of the electric field. Substituting into the previous equation and re-arranging it,
For the capacitor in the problem:
is the area of the plates
is the maximum electric field before a spark is produced
Solving for Q, we find the maximum charge that can be added before that occurs: