(a) The capacitance of the capacitor is:

and the voltage applied across its plates is

The relationship between the charge Q on each plate of the capacitor, the capacitance and the voltage is:

and re-arranging it we find the charge stored in the capacitor:

(b) The electrical potential energy stored in a capacitor is given by

where C is the capacitance and V is the voltage. The new voltage is

so the energy stored in the capacitor is
When the child is moving, he/she has kinetic energy. For just a brief second before they move the other way, the child is not moving, but they have gravitational potential energy.
The child may need a push from time to time because friction with the air causes loss of energy.
Answer:
Statement 2 is wrong
Explanation:
To check the statements in this exercise, let's describe the main properties of electromagnetic waves. Let's describe the characteristics
* they are transverse waves
* formed by the oscillations of the electric and magnetic fields
* the speed of the wave is the speed of light
with these concepts let's review the final statements
1) True. Formed by the oscillation of the two fields
2) False. They are transverse waves
3) True. Can travel by vacuum as they are supported by oscillations of the electric and magnetic fields
4) True. They all have the same speed of light
Statement 2 is wrong
Answer:
C. Gravitational forces only cause objects to be attracted to each
other, and magnetic and electric forces can cause objects to
attract or repel each other.
Electricity flows from positive to negative