IF YOU COULD PLEASE HELP ME!!! COULD YOU ALSO EXPLAIN HOW YOU DID IT? THANKS! a)
ID: 1527847 • Letter: I
Question
IF YOU COULD PLEASE HELP ME!!! COULD YOU ALSO EXPLAIN HOW YOU DID IT?
THANKS!
a) A proton with kinetic energy of 6.80 x 1006 eV is fired perpendicular to the face of a large plate that has a uniform charge density of +3.15 x 10-06 C/m2. What is the magnitude of the force on the proton? b) How much work must the electric field do on the proton to bring it to rest? Give only the magnitude of the work done c) From what distance should the proton be fired so that it stops right at the surface of the plate?
Explanation / Answer
as a matter of fact the strength of homogeneous lectric field of our plate is E=0.5*p/eps, where given p=3.15e-6 C/m^2, eps =8.854e-12;
so
a proton with kin energy w=6.80e6 eV =6.80-6 *1.6e-19 J will undergo a force F=e*E decelerating it, where e=1.602e-19 C is its charge;
1)
F=e*E =1.602e-19 * 0.5 *3.15e-6 /8.854e-12 =2.84e-14 N;
2)
work =w =6.80e6 *1.6e-19 =1.08e-12 Joules;
work done by the field is w= F*x, where x is the distance in question;
thus
3)
x= w/F =1.08e-12 / 2.84e-14 =3.83 m;