Answer:
resistance- decreases current-increases
Answer:
The principle of momentum conservation states that if there no external force the total momentum of the system before and after the collision is conserved.
Since momentum is a vector, we should investigate the directions and magnitudes of initial and final momentum.
![\vec{P}_{initial} = \vec{P}_{final}\\\vec{P}_{initial} = m_1\vec{v}_1 + 0\\\vec{P}_{final} = m_1\vec{v}_1' + m_2 \vec{v}_2'](https://tex.z-dn.net/?f=%5Cvec%7BP%7D_%7Binitial%7D%20%3D%20%5Cvec%7BP%7D_%7Bfinal%7D%5C%5C%5Cvec%7BP%7D_%7Binitial%7D%20%3D%20m_1%5Cvec%7Bv%7D_1%20%2B%200%5C%5C%5Cvec%7BP%7D_%7Bfinal%7D%20%3D%20m_1%5Cvec%7Bv%7D_1%27%20%2B%20m_2%20%5Cvec%7Bv%7D_2%27)
If the first ball hits the second ball with an angle, we should separate the x- and y-components of the momentum (or velocity), and apply conservation of momentum separately on x- and y-directions.
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).
Answer:
595391.482946 m/s
![3.21875\times 10^{6}](https://tex.z-dn.net/?f=3.21875%5Ctimes%2010%5E%7B6%7D)
Explanation:
E = Energy = 1.85 keV
I = Current = 5.15 mA
e = Charge of electron = ![1.6\times 10^{-19}\ C](https://tex.z-dn.net/?f=1.6%5Ctimes%2010%5E%7B-19%7D%5C%20C)
t = Time taken = 1 second
m = Mass of proton = ![1.67\times 10^{-27}\ kg](https://tex.z-dn.net/?f=1.67%5Ctimes%2010%5E%7B-27%7D%5C%20kg)
Velocity of proton is given by
![v=\sqrt{\dfrac{2E}{m}}\\\Rightarrow v=\sqrt{\dfrac{2\times 1.85\times 10^3\times 1.6\times 10^{-19}}{1.67\times 10^{-27}}}\\\Rightarrow v=595391.482946\ m/s](https://tex.z-dn.net/?f=v%3D%5Csqrt%7B%5Cdfrac%7B2E%7D%7Bm%7D%7D%5C%5C%5CRightarrow%20v%3D%5Csqrt%7B%5Cdfrac%7B2%5Ctimes%201.85%5Ctimes%2010%5E3%5Ctimes%201.6%5Ctimes%2010%5E%7B-19%7D%7D%7B1.67%5Ctimes%2010%5E%7B-27%7D%7D%7D%5C%5C%5CRightarrow%20v%3D595391.482946%5C%20m%2Fs)
The speed of the proton is 595391.482946 m/s
Current is given by
![I=\dfrac{\Delta Q}{t}\\\Rightarrow \Delta Q=It\\\Rightarrow \Delta Q=5.15\times 10^{-3}\times (1\ sec)\\\Rightarrow Q=5.15\times 10^{-3}\ C](https://tex.z-dn.net/?f=I%3D%5Cdfrac%7B%5CDelta%20Q%7D%7Bt%7D%5C%5C%5CRightarrow%20%5CDelta%20Q%3DIt%5C%5C%5CRightarrow%20%5CDelta%20Q%3D5.15%5Ctimes%2010%5E%7B-3%7D%5Ctimes%20%281%5C%20sec%29%5C%5C%5CRightarrow%20Q%3D5.15%5Ctimes%2010%5E%7B-3%7D%5C%20C)
Number of protons is
![n=\dfrac{Q}{e}\\\Rightarrow n=\dfrac{5.15\times 10^{-3}}{1.6\times 10^{-19}}\\\Rightarrow n=3.21875\times 10^{6}\ protons](https://tex.z-dn.net/?f=n%3D%5Cdfrac%7BQ%7D%7Be%7D%5C%5C%5CRightarrow%20n%3D%5Cdfrac%7B5.15%5Ctimes%2010%5E%7B-3%7D%7D%7B1.6%5Ctimes%2010%5E%7B-19%7D%7D%5C%5C%5CRightarrow%20n%3D3.21875%5Ctimes%2010%5E%7B6%7D%5C%20protons)
The number of protons is ![3.21875\times 10^{6}](https://tex.z-dn.net/?f=3.21875%5Ctimes%2010%5E%7B6%7D)