Answer:
Change in electric potential energy is -28.0 J
Explanation:
Electric potential energy is defined as the work is done to move a charge particle from one position to another in space in the presence of other charge particle or electric potential.
OR
Electric potential energy is also equal to the change in the configuration of the charge particles.
Thus,
Change in electric potential energy = - Work Done
According to the problem, Work Done is equal to 28 J. Thus,
Change in electric potential energy = -28 J
Answer:
0.02585 BTU
Explanation:
Given: Spring constant, k = 270 lbf/in
Initial force, f =100 lbf
Compression, x = 1 in
Work done can be calculated as follows:

The magnitude is doubled. The direction doesn't change.
Answer:
The volume of water is 139 mL.
Explanation:
Due to the Law of conservation of energy, the heat lost by coffee is equal to the heat gained by the water, that is, the sum of heats is equal to zero.

The heat (Q) can be calculated using the following expression:

where,
c is the specific heat of each substance
m is the mass of each substance
ΔT is the difference in temperature for each substance
The mass of coffee is:

Then,

The volume of water is:
