A proton beam, i.e. a continuous stream of individual protons, with an initial s
ID: 1654643 • Letter: A
Question
A proton beam, i.e. a continuous stream of individual protons, with an initial speed of 1.20 times 10^5 m/s(v_0) and traveling along the positive x axis centers a region of space, starting at the origin, in which a uniform electric field of unknown magnitude is directed relative to the proton's direction of motion as shown in the diagram at the right. It is observed that when the proton beam strikes a phosphorescent screen placed 24.0 cm from the origin and oriented perpendicular to the x axis, it has been deflected away from the x axis by a distance of 15.0 cm. Answer the following four questions. In what direction, as specified by a positive angle in degrees measured counterclockwise from the positive x axis, will the proton accelerate? How much time, in mu s, does is take a proton in the beam to go from, the origin to the screen? What magnitude of acceleration, in m/^2, has the proton experienced given the observed deflection? What is the magnitude, in N/C, of the electric field? Derive the equation, using integration of Coulomb's Law, for the magnitude of the electric field a distance d from the end of a thin rod of length L upon which a charge of Q has been uniformly distributed. See the diagram for clarification.Explanation / Answer
16) direction angle = 90 degree
It will accelerate in the direction of electric field.
17) time = distance /speed
= 0.24/(1.2*10^4)
= 20*10^-6 s
=20 us
If the answer doesn't match then make sure the speed given in question is 1.2*10^4 m/s
18) acceleration a = 2h/t^2
= 2*0.15/20e-6^2
= 7.5*10^8 m/s^2
19) Electric field E = F/q = ma/q
= 1.67e-27*7.5e8/1.6e-19
= 7.8281 N/C