Speed is a scalar quantity that refers to “how fast an object is moving.”
Power = 
Delilah: 170J/30s = 5.66 W
Adam: 260J/20s = 13 W
Answer:
0.0006091222 m
Explanation:
q = Charge = 42 pC
V = Voltage = 620 V
= Permittivity of free space = 
Electric potential is given by (at r = R)

The radius of the drop is 0.0006091222 m