Part a)
As we know that energy stored inside the capacitor is given as

for a given capacitor we know

Now we can use it in above equation to find the energy



PART b)
If two negative charges are hold near to each other and then released
Then due to mutual repulsion they start moving away from each other
Due to mutual repulsion as the two charges moving away the electrostatic potential energy of two charges will convert into kinetic energy of the two charges.
So here as they move apart kinetic energy will increase while potential energy will decrease
Part c)
As we know that capacitance is given as

here we know that




To find the x component use the following formula, where Ф = theta = the angle 'a' makes with the x axis.
Answer:
43.2 N
Explanation:
= Wavelength = 0.75 m
f = Frequency = 40 Hz
m = Mass of string = 0.12 kg
L = Length of string = 2.5 m
= Linear density = 
Velocity of wave is given by

The tension in string is given by

The tension in the string is 43.2 N
6 mph/s
Calculating acceleration involves dividing velocity by time — or in terms of SI units, dividing the meter per second [m/s] by the second [s]. Dividing distance by time twice is the same as dividing distance by the square of time. Thus the SI unit of acceleration is the meter per second squared .
Answer:

Explanation:
Kinetic energy is energy due to motion. The formula is half the product of mass and velocity squared.

The mass of the roller coaster car is 2000 kilograms and the car is moving 10 meters per second.
Substitute these values into the formula.

Solve the exponent.
- (10 m/s)²= 10 m/s * 10 m/s= 100 m²/s²

Multiply the first two numbers together.

Multiply again.

- 1 kilogram square meter per square second is equal to 1 Joule.
- Our answer of 100,000 kg*m²/s² is equal to 100,000 Joules.

The roller coaster car has <u>100,000 Joules</u> of kinetic energy.