Classics.
Resistance is equal to relation between voltage and current.

If we express current:

If current is in fact 0 then one of the quantities either voltage or resistance must be equal to zero. Since resistance cannot be equal 0, because that would violate mathematical law that states that division by zero is undefined the only logical conclusion is voltage.
So the answer should be C voltage and B zero.
Hope this helps!
Explanation:
a. Average speed = distance / time
= 100 m / 70 s
= 1.43 m/s
b. Average displacement = displacement / time
= 0 m / 70 s
= 0 m/s
Distance is the length of the path traveled. Displacement is the difference between the final position and initial position.
Answer:
Explanation:
Time taken to complete one revolution is called time period.
So, Time period, T = 1 s
Diameter = 1.6 mm
radius, r = 0.8 mm
Let the angular speed is ω.
The relation between angular velocity and the time period is

ω = 2 x 3.14 = 6.28 rad/s
The relation between the linear velocity and the angular velocity is
v = r x ω
v = 0.8 x 10^-3 x 6.28
v = 0.005 m/s
the upward force the desk pushes on the book.
from the free body diagram of the book, it is clear that on the book, there are two forces acting.
1) normal force F by the desk in Upward direction.
2) force of gravity by earth in downward direction.
The Upward normal force by the desk on the book balances the force of gravity by earth in downward direction. that is why the book remains stationary on the desk.
What does this supposed to mean?