Answer:
0.0979 N/c
Explanation:
Electric field, E is given as a product of resistivity and current density
E=jP where P is resistivity and j is current density
But the current density is given as
where I is current and A is area and 
Substituting this into the first equation then 
Given diameter of 0.259 cm= 0.00259 m and the radius will be half of it which is 0.001295 m
Answer: The correct answer is "No".
Explanation:
Gravity: It is the force which causes object to fall on the earth. It is the force which attracts bodies towards each other.
Potential difference: It is defined as the potential acting between the two points. The work done in moving the unit positive charge from one location to the another location.
The potential difference in battery is caused by the electrodes. There are two terminals in battery: Negative terminal which is at lower potential and Positive terminal which is at higher potential. It forces the electrons to flow in the circuit which constitutes the current.
The gravity and the potential difference have no relation between them.
Therefore, gravity have no effect on the potential difference of a battery.
<u>Answer </u>
A. that the initial gravitational potential energy of the masses transformed into kinetic energy of the paddles and then to thermal energy in the water
<u>Explanation</u>
James Joule allowed some water to fall from a height of 1 foot. the water would turn a paddle wheel at the bottom causing a temperature of water to raise.
The height form which the water fell, mass and the temperature of water was measured and used to calculate mechanical equivalent of heat.
From the choices given the best answer is A. that the initial gravitational potential energy of the masses transformed into kinetic energy of the paddles and then to thermal energy in the water.
Weight = (mass) x (gravity)
120 N = (mass) x (9.8 m/s²)
Mass = (120 N) / (9.8 m/s²)
Mass = 12.24 kg (B)
