Answer:
3.6 x 10^8 V
Explanation:
Q = 4 m C = 4 x 10^-3 C
r = 5 cm = 0.05 m
The formula for the potential at the surface is
Vs = K Q / r = (9 x 10^9 x 4 x 10^-3) / 0.05 = 7.2 x 10^8 V
The formula for the potential at the centre is
Vc = 3/2 Vs
Vc = 1.5 x 7.2 x 10^8 V = 10.8 x 10^8 V
The difference in potential is
V = Vc - Vs = 10.8 x 10^8 - 7.2 x 10^8 = 3.6 x 10^8 V
The idea of a mechanical device, like a wind up toy, is to take take advantage of the laws of thermodynamics in order to perform some kind of work.
In the case of a wind up toy, mechanical energy (winding the handle) is stored as potential energy in an internal spring. This creates a state of 'low entropy' in the toy since work was done to concentrate energy in the spring.
The natural tendency of the spring is to unwind and distribute it's energy in a more disordered fashion, thereby increasing entropy and following the laws of thermodynamics.
The mechanism inside the toy is engineered to focus the flow of energy being delivered by the spring into a specific mechanical motion (Kinetic Energy), then sound (air pressure) and finally heat (thermal energy).
Answer:
1.45
Explanation:
Refractive index of the liquid is given as;
Refractive index = ![\frac{speed of light in vacuum}{speed of light in liquid}](https://tex.z-dn.net/?f=%5Cfrac%7Bspeed%20of%20light%20in%20vacuum%7D%7Bspeed%20of%20light%20in%20liquid%7D)
But,
speed = ![\frac{distance}{time}](https://tex.z-dn.net/?f=%5Cfrac%7Bdistance%7D%7Btime%7D)
Since a certain light of specific wavelength was used during the same time, let the time be represented by t.
So that;
speed of light in vacuum = ![\frac{3500}{t}](https://tex.z-dn.net/?f=%5Cfrac%7B3500%7D%7Bt%7D)
speed of light in the liquid = ![\frac{2350}{t}](https://tex.z-dn.net/?f=%5Cfrac%7B2350%7D%7Bt%7D)
Refractive index =
÷ ![\frac{2350}{t}](https://tex.z-dn.net/?f=%5Cfrac%7B2350%7D%7Bt%7D)
=
x ![\frac{t}{2350}](https://tex.z-dn.net/?f=%5Cfrac%7Bt%7D%7B2350%7D)
Refractive index = ![\frac{3500}{2350}](https://tex.z-dn.net/?f=%5Cfrac%7B3500%7D%7B2350%7D)
= 1.4536
= 1.45
The refractive index of the liquid is 1.45.