In the following figure m1 = 21.0 kg and α = 52.5. The coefficient of kinetic friction between the block and the incline is μk = 0.40

electric field is a function of 1/r^2

yes, the force per unit charge for a point charge is inverse square law.

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