Answer:

Explanation:
Potential difference between two points in constant electric field is given by the formula

here we know that

also we know that

now we have

now change in potential energy is given as



You'd use the equation kinetic energy=mass*0.5*speed^2
So you'd rearrange this to get mass =kinetic energy /0.5 *speed^2
Which is mass= 1500J/0.5*35^2
=2.44897959183673469........kg
True a change in temperature can cause a change in density.
If you look at a atom under a electron microscope you would use it