Question

A proton accelerates from rest in a uniform electric field of 620 N/C. At one later moment, its speed is 1.30 Mm/s (nonrelativistic because v is much less than the speed of light).

(a) Find the acceleration of the proton.
m/s2

(b) Over what time interval does the proton reach this speed?
s

(c) How far does it move in this time interval?
m

(d) What is its kinetic energy at the end of this interval?
J

=====================

I've solved:

1.30Mm x (1m/1000Mm) = .0013
(.0013)(620)/(1.67x10e-27) = 4.826e26,

but I got the wrong answer. What am I doing wrong? If i can get part A right I can do the rest.

Answer 1

You did some strange calculations. Your unit factor is silly. Mm is not millimeters, it is Megameters.

F=ma
a= F/m=Eq/m YOu know E (in N/C), you know the mass and charge on a proton.

F*deltaTime= mv
Eq*deltaTime=mv
solve for deltaTime