Answer:
Sound waves are pushed closer together, decreasing wavelength
and increasing frequency.
Answer:
122.84 J
Explanation:
Since plate is square, area, A is given by 
The distance between plates, d, is given in the question as 2mm=0.002m
Charge on plate, Q, as given in the question is 240 
Assuming mica dielectric constant, k of 7
Capacitance, C is given by
C=
Stored energy, E is given by
E=
Therefore, the stored energy is 122.84 J
Answer:
1750 Joules.
Explanation:
Work done = force * distance
= 7 * 250
= 1750 Joules.
Answer:
d) The stone will have about 50 joules of kinetic energy and 0 joules of potential energy .
Explanation:
Given :
Initial Potential energy ,
.
Initial Kinetic energy ,
. ( because ball is in rest )
Now , we know , kinetic energy is maximum when an object reaches ground .
Also , potential energy is zero when an object is in ground .
We know , by conservation of energy :
Initial total energy = Final total energy

Therefore , option d) is correct .