It's 3.6 meters per second less than my speed was
at 4:19 PM last Tuesday.
Does that tell you anything ?
Why not ?
Answer: C.
Explanation:
For a parallel-plate capacitor where the distance between the plates is d.
The capacitance is:
C = e*A/d
You can see that the distance is in the denominator, then if we double the distance, the capacitance halves.
Now, the stored energy can be written as:
E = (1/2)*Q^2/C
Now you can see that in this case, the capacitance is in the denominator, then we can rewrite this as:
E = (1/2)*Q^2*d/(e*A)
e is a constant, A is the area of the plates, that is also constant, and Q is the charge, that can not change because the capacitor is disconnected.
Then we can define:
K = (1/2)*Q^2/(e*A)
And now we can write the energy as:
E = K*d
Then the energy is proportional to the distance between the plates, this means that if we double the distance, we also double the energy.
1 gallon = 231 cubic inches
1 cubic foot = 1728 cubic inches
(55 gal) x (231 in³/gal) x (1 ft³/1728 in³)
= (55 x 231 / 1728) ft³
= 7.352 cubic feet (rounded)
Answer:
v = 5.9 x 10⁷ m/s
Explanation:
The kinetic energy of the electron in terms of potential difference is given as:
--------------- equation (1)
where,
e = charge on electron = 1.6 x 10⁻¹⁹ C
V = Potential Difference = 9.9 KV = 9900 Volts
The kinetic energy in general is given as:
--------- equation (2)
where,
m = mass of electron = 9.1 x 10⁻³¹ kg
v = speed of electron = ?
Therefore, comparing equation (1) and equation (2), we get:
<u>v = 5.9 x 10⁷ m/s</u>
