Question

An electron and a proton are released simultaneously from rest and start moving toward each other due to their electrostatic attraction, with no other forces present. Which of the following statements are true just before they are about to collide?

A) They are closer to the to the initial position of the electron that to the initial position of the proton.
B) They are closer to the to the initial position of the proton that to the initial position of the electron.
C) The electrostatic force on the proton is greater than the electrostatic force on the electron.
D) They both have the same speed.
E) They are at the midpoint of their initial separation.

Answer 1

B) They are closer to the to the initial position of the proton that to the initial position of the electron.

Step-by-step explanation:

As we know that electron and proton both are moving due to mutual electrostatic attraction force

So the force between them is given as

`F = (k(e)(e))/(r^2)`

now since it follows Newton's III law so they both will have equal and opposite force on each other

Now the acceleration of the electron and proton is given as

`a_e = (F)/(m_e)`

acceleration of proton is given as

`a_p = (F)/(m_p)`

since acceleration of electron is much larger than the acceleration of proton

so electron will move more distance hence correct answer will be

B) They are closer to the to the initial position of the proton that to the initial position of the electron.