Answer:
27J
Explanation:
From conservation of Thermal energy, the total internal energy is the total sum of energy supplied or taken from the system plus work done for or on the system.
Now the change in internal energy would be the sum of the received energy substended in the gas plus the work done by the system which is workdone that it will sustend in pushing the lid. This is expressed mathematically as;
U = Q + (F×d);
U- change in internal energy
Q is the energy received by the system and is positive when energy is received by the system.
Fxd is the workdone and is positive since the gas pushes up the lid- the system does work.
U=12+(3×5)= 27J
Answer:
D: The distance between the particles decreases
Explanation:
Taking away energy slows down molecules, like how you slow down when you are cold (I think)
Answer:
C. The number of positive and negative charges can be the same.
Explanation:
Answer:
d)
Explanation:
Electrons are lost or gained when the ballon is rubbed with a PVC. As the rubber ballon lost electrons, it will have more protons, hence the positive charge. (More protons than electrons in the ballon).
Answer:
c) 
Explanation:
Coulomb's law says that the force exerted between two charges is inversely proportional to the square of distance between them, and is given by the expression:

where k is a proportionality constant with the value 
In this case
, so we have:

Solving the equation for q, we have:



Replacing the given values:

