Skip to main content
Ch.5 - Thermochemistry

Chapter 5, Problem 28a

Consider a system consisting of two oppositely charged spheres hanging by strings and separated by a distance r1, as shown in the accompanying illustration. Suppose they are separated to a larger distance r2, by moving them apart. (a) What change, if any, has occurred in the potential energy of the system?

Verified Solution
Video duration:
1m
This video solution was recommended by our tutors as helpful for the problem above.
593
views
Was this helpful?

Video transcript

Hi everyone for this problem, we're told to consider a system consisting of two spheres of identical charge and a frictionless plane separated by 10 cm. If the distance between the sphere is decreased, what happens to the potential energy of the system? Okay, so we want to know what happens to the potential energy and we're going to need our potential energy equation for this. And that is, potential energy is equal to K times Q, one times Q two over R. So for this problem, we're looking at two variables here, we're looking at our potential energy variable and we're looking at R which stands for distance. So we're told that we have two charges. So we'll just say that we have two positive charges And they're separated by a distance of 10 cm. So if this distance is decreased, we want to know what happens to the potential energy. So we see here we have an inverse relationship with these two variables. So if our if our distance is decreasing, that means our potential energy is going to increase. Okay, so that is the answer to this problem. It is that the electrostatic potential energy of the system increases as the separation between the like charged particles decreases. Alright, that's the end of this problem. I hope this was helpful
Related Practice
Textbook Question

For the following processes, calculate the change in internal energy of the system and determine whether the process is endothermic or exothermic: (a) A balloon is cooled by removing 0.655 kJ of heat. It shrinks on cooling, and the atmosphere does 382 J of work on the balloon.

973
views
Textbook Question

A gas is confined to a cylinder fitted with a piston and an electrical heater, as shown here:

Suppose that current is supplied to the heater so that 100 J of energy is added. Consider two different situations. In case (1) the piston is allowed to move as the energy is added. In case (2) the piston is fixed so that it cannot move. (a) In which case does the gas have the higher temperature after addition of the electrical energy?

752
views
Textbook Question

A gas is confined to a cylinder fitted with a piston and an electrical heater, as shown here:

Suppose that current is supplied to the heater so that 100 J of energy is added. Consider two different situations. In case (1) the piston is allowed to move as the energy is added. In case (2) the piston is fixed so that it cannot move. (b) Identify the sign (positive, negative, or zero) of q and w in each case?

511
views
Textbook Question

(c) Is the volume of a system a state function? Why or why not?

475
views
Textbook Question
During a deep breath, our lungs expand about 2.0 L against an external pressure of 101.3 kPa. How much work is involved in this process (in J)?
573
views
Textbook Question
How much work (in J) is involved in a chemical reaction if the volume decreases from 33.6 L to 11.2 L against a constant pressure of 90.5 kPa?
746
views