Answer: 3.12 * 10^12 F ( 3.12 pF)
Explanation: To calculate this capacitor of two hollow, coaxial, iron cylinders, we have to determine the potental differente between them and afeter that to use C=Q/ΔV
The electric field in th eregion rinner<r<router
By using the Gaussian law
∫E*ds=Q inside/εo
E*2*π*rinner^2*L= Q /εo
E=Q/(2*π*εo*r^2)
[Vab]=\int\limits^a_b {E} \, dr
where a and b are the inner and outer radii.
Then we have:
ΔV= 2*k*(Q/L)* ln (b/a)
replacing the values and using that C=Q/ΔV
we have:
C= L/(2*k*ln(b/a)=0.17/(2*9*10^9*3.023)=3.12 pF
Change in velocity = Final velocity - Initial velocity
Initial velocity = 20 m/s
Final velocity = 10 m/s
Change in velocity = 10 - 20 = -10m/s
Correct option B
Hope This Helps You!
Correct answer is A
Voltaic Piles
Explanation:
When a car is breaking, the brakes apply pressure/force onto the wheels(car) which allows it to slow down.
When the car collides with an object, it is exerting a force upon that object to which it applies an equal and opposite force on the car.
I think this is what you are asking for.
Hope This Helps :)