- #1
doggydan42
- 170
- 18
Homework Statement
From a distance of 10 cm, a proton is projected with a speed of ##v = 4.0 × 106 \frac{m}{s}## directly at a large, positively charged plate whose charge density is ##\sigma = 2.0 × 10^{-5} \frac{C}{m^2}##. (See below.) (a) Does the proton reach the plate? (b) If not, how far from the plate does it
turn around?
Homework Equations
$$\vec E = \frac{1}{4\pi \varepsilon_0} \int_{Surface} \frac{\sigma}{r^2} \,dA \hat r$$
The Attempt at a Solution
I understand that once you find the electric field, you can multiply by the charge to find the force, than set that equal to ##m\vec a## and solve for a knowing the mass of the proton. Then use kinematics to find how far it will travel.
Though to find the electric field, I am unsure of how to set ##dA##, ## \hat r##, and ##r##. I am also unsure of what to integrate over.
Thank you in advance.