A piano has a mass of 99 kg. What is the weight of the piano?

Explanation:

weight of the piano = mg

w = 99 x 10 =990 N

if they have a finite resultant

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