Answer:
C).
Explanation:
As we know that capacitance of a given capacitor is
now we know that energy stored in the capacitor plates
here if all the dimensions of the capacitor plate is doubled
then in that case
here area becomes 4 times on doubling the radius and the distance between the plates also doubles
So new capacitance is now
so capacitance is doubled
now the final energy stored between the plates of capacitor is given as
so the final energy is
Answer:
There is an interval of 24.28s in which the rocket is above the ground.
Explanation:
From Kinematics, the position as a function of time when the engine still works will be:
At what time the altitud will be ?
⇒
Using the quadratic formula: .
How much time does it take for the rocket to touch the ground? No the function of position is:
Where our new initial position is , the velocity when the engine breaks is
and the only acceleration comes from gravity (which points down).
Now, when the rocket tounches the ground:
Again, using the quadratic ecuation:
Now, the total time from the moment it takes off and the moment it tounches the ground will be:
.