3.what does this stand for ??

see below

Explanation:

The triangle stands for the change in

We would change the change in x

Δ This is the symbol of Delta which means Change

and x is length/distance/position.

Thus, Δx stands for Change in length/distance/position.

-TheUnknownScientist

electrical potential energy =0.072 j

explanation:

electrical potential energy is given by

u= q δv

q= charge=6 c

δv= potential difference and is given by

δv= e d

e= electric field

d= distance=5 mm=0.005 m

δv=2.4 (0.005)=0.012 v

now electric potential energy= u= q δv

u=6 (0.012)

u=0.072 j