An electron is held at a distance from a stationary, positively charged object . if the electron is released , what energy change will take place?

Electrostatic potential energy will convert into kinetic energy

Explanation:

When electron is released from rest at some distance from positive charge then due to electrostatic attraction force these two charges will attract each other.

Now in the form of energy we can say that

electrostatic potential energy =

now as the two charges comes closer to each other then the electrostatic potential energy will decrease and hence this energy will convert into kinetic energy of two charges

so we can say

no. dot product   =0 when vecs at right angles

wavelength divides in half and speed stays the same.