Answer: a) 127 eV; b) there is no change of kinetic energy.
Explanation: In order to explain this problem we have to use the change of potentail energy ( conservative field) is equal to changes in kinetic energy. So for the proton ther move to lower potential then they gain kinetic energy from the electric field. This means the electric force do work in this trayectory and then the protons increased changes its speed.
If we replace the proton by a electron we have a very different situaction, the electrons are located in a lower potental then they can not move to higher potential if any external force does work on the system.
In resumem, the electrons do not move from a point with V=87 to other point with V=-40 V. The electric force point to high potential so the electrons can not move to lower potential region (V=-40V).
When you heat a certain substance with a difference of temperature
![\Delta T](https://tex.z-dn.net/?f=%5CDelta%20T)
the heat (energy) you must give to it is
![E(=Q) =mc\Delta T](https://tex.z-dn.net/?f=E%28%3DQ%29%20%3Dmc%5CDelta%20T)
where
![c](https://tex.z-dn.net/?f=c)
is the specific heat of that substance (given in J/(g*Celsius))
In this case
![E=645*0.3850*(28.22-13.20) =3729.8 (Joule)](https://tex.z-dn.net/?f=E%3D645%2A0.3850%2A%2828.22-13.20%29%20%3D3729.8%20%28Joule%29)
Observation: the specific heat of a substance is given in J/(g*Celsius) or J/(g*Kelvin) because on the temperature scale a
difference of 1 degree Celsius = 1 degree Kelvin
Answer:
distance between both oasis ( 1 and 2) is 27.83 Km
Explanation:
let d is the distance between oasis1 and oasis 2
from figure
OC = 25cos 30
OE = 25sin30
OE = CD
Therefore BC = 30-25sin30
distance between both oasis ( 1 and 2) is calculated by using phytogoras theorem
in![\Delta BCO](https://tex.z-dn.net/?f=%5CDelta%20BCO)
![OB^2 = BC^2 + OC^2](https://tex.z-dn.net/?f=OB%5E2%20%3D%20BC%5E2%20%2B%20OC%5E2)
PUTTING ALL VALUE IN ABOVE EQUATION
![d^2 = 930-25sin30)^2 + (25cos30)^2](https://tex.z-dn.net/?f=d%5E2%20%3D%20930-25sin30%29%5E2%20%2B%20%2825cos30%29%5E2)
![d^2 = 775](https://tex.z-dn.net/?f=d%5E2%20%3D%20775)
d = 27.83 Km
distance between both oasis ( 1 and 2) is 27.83 Km