Answer:
c. 0.02 C and 4 J
Explanation:
Applying,
Q = CV................ Equation 1
Where Q = Charge, C = Capacitance of the capacitor, V = Voltage.
From the question,
Given: C = 50 μF = 50×10⁻⁶ F, V = 400 V
Substitute these values into equation 1
Q = (50×10⁻⁶)(400)
Q = 0.02 C.
Also Applying
E = CV²/2............. Equation 2
Where E = Energy stored.
Therefore,
E = (50×10⁻⁶ )(400²)/2
E = 4 J
Hence the right option is c. 0.02 C and 4 J
1. Sound insulation at construction sides.
2. Using silencers in automobiles and replacing old noisy machines with new quitter machines or using lubricants
Answer:

Explanation:
The work done on the object at rest is all converted into kinetic energy, so we can write

Or, re-arranging for v,

where
v is the final speed of the object
W is the work done
m is the object's mass
If the work done on the object is doubled, we have W' = 2W. Substituting into the previous formula, we can find the new final speed of the object:

So, the new speed of the object is
.
We will apply the equation:
2as = v² - u²
v = √(2as + u²)
v = √(2 x 4 x 400 + 13²)
v = 58 m/s
hope this helps