Answer: find the answer in the explanation
Explanation: The potential energy in a circuit between two points is the workdone in taking units positive charge from one point to the other in the circuit. Its S.I unit is Joule.
Because voltage of a battery or cell in a circuit is the potential energy difference across its terminal
The potential energy difference between two points is one volt, if the workdone in taking one Coulomb of positive charge from one point to the other is one Joule.
Answer:

Explanation:
Work is given by the equation
where
is force and
is displacement.
Displacement is defined as change in position. In this case, the box moves from 5m to 20m. Its displacement is
.
The force acting on the box is the force of gravity, given as
.
Therefore, the total work done is:
(two significant figures).
Answer:
Explanation:
The force of gravity depends directly upon the masses of the two objects, and inversely on the square of the distance between them. This means that the force of gravity increases with mass, but decreases with increasing distance between objects
so a option is correct
P is disproportional to t, which means that if P increases with x factor, the t will decrease with the same x factor. If t increases then P decreases
Answer:
7.894 MJ
Explanation:
Given that:
The mass of the saturated water vapor = 3.7 kg
The pressure of the saturated water vapor = 0.4 MPa
From saturated properties of steam tables when the pressure is at 0.4 Mpa
The enthalpy in (kJ/kg);
hf = 604.7 kJ/kg
hg = 2738.1 kJ/kg
The rejected heat during this process is:
Q = m(hg - hf)
Q = 3.7(2738.1 - 604.7) kJ/kg
Q = 3.7(2133.4) kJ/kg
Q = 7893.58 kJ/kg
Q = 7.894 MJ