1) 
The capacitance of a parallel-plate capacitor is given by:

where
is the vacuum permittivity
A is the area of each plate
d is the distance between the plates
Here, the radius of each plate is

so the area is

While the separation between the plates is

So the capacitance is

And now we can find the energy stored,which is given by:

2) 0.71 J/m^3
The magnitude of the electric field is given by

and the energy density of the electric field is given by

and using
, we find

Answer:
The final velocity of 18 kg ball is
= 42.09 
Explanation:
Mass of first ball
= 18 kg
Mass of second ball
= 47 kg
Initial velocity of 18 kg ball
= 76 
Initial velocity of 47 kg ball = 0
Final velocity of 18 kg ball
= ??
Final velocity of 18 kg ball is given by the formula
= 
Put all the values in above formula we get
= 2 × 18 × 
= 42.09 
Thus, the final velocity of 18 kg ball is
= 42.09 
Answer:
20
Explanation:
20 multiplied by 2
hope i hv answered ur question
Answer:
0.0109 m ≈ 10.9 mm
Explanation:
proton speed = 1 * 10^6 m/s
radius in which the proton moves = 20 m
<u>determine the radius of the circle in which an electron would move </u>
we will apply the formula for calculating the centripetal force for both proton and electron ( Lorentz force formula)
For proton :
Mp*V^2 / rp = qp *VB ∴ rp = Mp*V / qP*B ---------- ( 1 )
For electron:
re = Me*V/ qE * B -------- ( 2 )
Next: take the ratio of equations 1 and 2
re / rp = Me / Mp ( note: qE = qP = 1.6 * 10^-19 C )
∴ re ( radius of the electron orbit )
= ( Me / Mp ) rp
= ( 9.1 * 10^-31 / 1.67 * 10^-27 ) 20
= ( 5.45 * 10^-4 ) * 20
= 0.0109 m ≈ 10.9 mm