Activity 1 — Electric Fields
Imagine an isolated positive point charge with a charge 𝑄 (many times larger than the charge on a single electron).
If the total positive charge is 𝑄 = 1.62 × 10-6 C, what is the magnitude of the electric field caused by this charge at point P, a distance d = 1.53 m from the charge?
What is the direction of the electric field at point P?
Now find the magnitude of the force on an electron placed at point P. Recall that the charge on an electron has magnitude e = 1.60 × 10-19 C.
A Proton between Oppositely Charged Plates
A uniform electric field exists in the region between two oppositely charged parallel plates 1.51 cm apart. A proton is released from rest at the surface of the positively charged plate and strikes the surface of the negative plate in a time interval 1.58 × 10−6 s.
Find the magnitude of the electric field. (Use 1.60 × 10−19 C for the magnitude of the charge on an electron and 1.67 × 10−27 kg for the mass of a proton.)
Find the speed of the proton at the moment it strikes the negatively charged plate.
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