A proton is observed to have an instantaneous acceleration of 10 × 1011 m/s². What is the magnitude E of the electric field at the proton's location? i N/C

An electron is in a uniform upward-pointing electric field. a. If the electron experiences a downward acceleration of 9.81 m/s2, what is the magnitude of the electric field? (Ignore gravity.) b. What is the gravitational force on this electron? Is it okay to ignore gravity? Explain.

A proton accelerates from rest in a uniform electric field of 640. N/C At some later time, its speed is 1.20 106 m/s. (a) Find the magnitude of the acceleration of the proton. (b) How long does it take the proton to reach this speed? (c) How far has it moved in that interval? (d) What is its kinetic energy at the later time?

(a) Find the electric field at x = 5.00 cm in Figure 18.52 (a), given that q = 1.00 C. (b) at what position between 3.00 and 8.00 cm is the total electric field the same as that for ? 2q alone? (c) Can the electric field be zero anywhere between 0.00 and 8.00 cm? (d) At very large positive or negative values of x, the electric field approaches zero in both (a) and (b). In which does it most rapidly approach zero and why? (e) At what position to the light of 11.0 cm is the total electric field zero, other than at infinity? (Hint: A graphing calculator can yield considerable insight in this problem.)