An electron is released from rest at a distance of 6.00 cm from a proton. if the proton is held in place, how fast will the electron be moving when it is 3.00 cm from the proton?

91.87 m/s

Explanation:

Given:

Assume:

We know that only only electric field due to proton causes to move from a distance of 6 cm from proton to 3 cm distance from it. This means the electric force force does work on the electron to move it from one initial position to the final position which is equal to the change in potential energy of the electron due to proton.

Now, according to the work-energy theorem, the total work done by the electric force on the electron due to proton is equal to the kinetic energy change in it.

Hence, when the electron is at a distance of c cm from the proton, it moves with a velocity of 91.87 m/s.

d

explanation:

v=uf/(u-f)

= 5.10/(5-10) convex lens has positive focal length

=50/-5

=-10 cm (formed at other side)