Answer
Integral EdA = Q/εo =C*Vc(t)/εo = 3.5e-12*21/εo = 4.74 V∙m <----- A)
Vc(t) = 21(1-e^-t/RC) because an uncharged capacitor is modeled as a short.
ic(t) = (21/120)e^-t/RC -----> ic(0) = 21/120 = 0.175A <----- B)
Q(0.5ns) = CVc(0.5ns) = 2e-12*21*(1-e^-t/RC) = 30.7pC
30.7pC/εo = 3.47 V∙m <----- C)
ic(0.5ns) = 29.7ma <----- D)
Conservation law, also called law of conservation, in physics, several principles that state that certain physical properties (i.e., measurable quantities) do not change in the course of time within an isolated physical system
The increase in temperature of the metal hammer is 0.028 ⁰C.
The given parameters:
- <em>mass of the metal hammer, m = 1.0 kg</em>
- <em>speed of the hammer, v = 5.0 m/s</em>
- <em>specific heat capacity of iron, 450 J/kg⁰C</em>
The increase in temperature of the metal hammer is calculated as follows;

where;
<em>c is the </em><em>specific heat capacity</em><em> of the metal hammer</em>
<em />
Assuming the metal hammer is iron, c = 450 J/kg⁰C

Thus, the increase in temperature of the metal hammer is 0.028 ⁰C.
Learn more about heat capacity here: brainly.com/question/16559442