Potassium iodide
Molar mass: 166.0028 g/mol
Formula: KI
Answer and explanation:
A correct option is an option (B).
The electrical force between two charges is given as,

The electrical force is directly proportional to the product of two charges. Thus Force will depend on two charges irrespective of their signs.
Option (A) is incorrect because if charges are opposite, the value of force will not be zero. It will be -ve.
Option (C) is incorrect because the force is directly proportional to the product of charges, it depends on the amount of charge.
Option (D) is also incorrect because the force in inversly proportional to the distance between two charges. Thus, if the distance between two charges is increased, the force between two charges will decrease.
Concllusion:
The correct option is option (B).
Answer:
v = 72 km / h
Explanation:
The definition of average speed is the distance traveled between the time interval
v = Δx / Δt
let's find the distance traveled
x = 60 + 30
x = 90 km
time spent, all time must be included, travel time and when stopped
t = 0.45 + 0.15 + 0.5+ 0.15
t = 1.25 h
we substitute in the initial equation
v = 90 / 1.25
v = 72 km / h
in going from one city to the other
Answer: 52%
Explanation:
1W = 1 J/s
motor input is 10000 J/s
Potential energy change
PE = 955(9.81)(25.0) = 234,213.75
power needed to change the PE in that time
P = 234,213.75/ 45 = 5,204.75 Watts
motor is 5204.75 / 10000 = 0.520475 or 52% efficient
Answer:
3.6 x 10^8 V
Explanation:
Q = 4 m C = 4 x 10^-3 C
r = 5 cm = 0.05 m
The formula for the potential at the surface is
Vs = K Q / r = (9 x 10^9 x 4 x 10^-3) / 0.05 = 7.2 x 10^8 V
The formula for the potential at the centre is
Vc = 3/2 Vs
Vc = 1.5 x 7.2 x 10^8 V = 10.8 x 10^8 V
The difference in potential is
V = Vc - Vs = 10.8 x 10^8 - 7.2 x 10^8 = 3.6 x 10^8 V