Answer:
3. none of these
Explanation:
The rotational kinetic energy of an object is given by:

where
I is the moment of inertia
is the angular speed
In this problem, we have two objects rotating, so the total rotational kinetic energy will be the sum of the rotational energies of each object.
For disk 1:

For disk 2:

so the total energy is

So, none of the options is correct.
Answer:
8, 8 W
Explanation:
The useful power of 1 Light Emitting Diode is

Total power required is 1.6 W
Number of Light Emitting Diodes would be

The number of Light Emitting Diodes is 8.
Power would be

The power that is required to run the Light Emitting Diodes is 8 W
Answer: 14.52*10^6 m/s
Explanation: In order to explain this problem we have to consider the energy conservation for the electron within the coaxial cylidrical wire.
the change in potential energy for the electron; e*ΔV is equal to energy kinetic gained for the electron so:
e*ΔV=1/2*m*v^2 v^=(2*e*ΔV/m)^1/2= (2*1.6*10^-19*600/9.1*10^-31)^1/2=14.52 *10^6 m/s
Answer:
E=0
Explanation:
Electric field due to each thin sheet of charge=\sigma/2\varepsilon
let us say the right plate has positive charge density \varepsilonand left sheet has a negative charge density -\varepsilon .
In the region between the plates,the electric field due to each plate is in same direction,
E=\sigma/2\varepsilon-(-\sigma/2\varepsilon)
E=\sigma/\varepsilon
in the region outside the plates, the field due to the plates is in opposite directions
E=-\sigma/2\varepsilon-(-\sigma/2\varepsilon)
E=-\sigma/2\varepsilon+\sigma/2\varepsilon
E=0