Two identical, metal spheres have different charges. Sphere 1 has a charge of
. Sphere 2 has 30 excess electrons. If the two spheres are brought into contact and then separated, what charge will each have? How many electrons does this correspond to?
We need to determine what will happen to the charge when the spheres touch. They are metal spheres so we know they will be conductors. This means that the charge is able to move so when they touch it is possible for the charge on each sphere to change. We know that charge will redistribute evenly across the two spheres because of the forces between the charges. We need to know the charge on each sphere, we have been given one.
This problem is similar to the earlier worked example. This time we have to determine the total charge given a certain number of electrons. We know that charge is quantized and that electrons carry the base unit of charge which is
. The total charge will therefore be:
As the spheres are identical in material, size and shape the charge will redistribute across the two spheres so that it is shared evenly. Each sphere will have half of the total charge:
So each sphere now has:
of charge.
We know that charge is quantized and that electrons carry the base unit of charge which is
.
As each electron carries the same charge the total charge must be made up of a certain number of electrons. To determine how many electrons we divide the total charge by the charge on a single electron:
Summary
Objects can be
positively charged,
negatively charged or
neutral .
Objects that are neutral have equal numbers of positive and negative charge.
Unlike charges are attracted to each other and like charges are repelled from each other.
Charge is neither created nor destroyed, it can only be transferred.
Charge is measured in coulombs (C).
Conductors allow charge to move through them easily.
Insulators do not allow charge to move through them easily.
The following presentation is a summary of the work covered in this chapter. Note that the last two slides are not needed for exam purposes, but are included for general interest.
End of chapter exercise
What are the two types of charge called?
Provide evidence for the existence of two types of charge.
Fill in the blanks: The electrostatic force between like charges is
while the electrostatic force between opposite charges is
.
I have two positively charged metal balls placed 2 m apart.
Is the electrostatic force between the balls attractive or repulsive?
If I now move the balls so that they are 1 m apart, what happens to the strength of the electrostatic force between them?
I have 2 charged spheres each hanging from string as shown in the picture below.
Choose the correct answer from the options below:
The spheres will
swing towards each other due to the attractive electrostatic force between them.
swing away from each other due to the attractive electrostatic force between them.
swing towards each other due to the repulsive electrostatic force between them.
swing away from each other due to the repulsive electrostatic force between them.
Describe how objects (insulators) can be charged by contact or rubbing.
You are given a perspex ruler and a piece of cloth.
How would you charge the perspex ruler?
Explain how the ruler becomes charged in terms of charge.
How does the charged ruler attract small pieces of paper?
[IEB 2005/11 HG] An uncharged hollow metal sphere is placed on an insulating stand. A positively charged rod is brought up to touch the hollow metal sphere at P as shown in the diagram below. It is then moved away from the sphere.
Where is the excess charge distributed on the sphere after the rod
has been removed?
It is still located at point P where the rod touched the sphere.
It is evenly distributed over the outer surface of the hollow sphere.
It is evenly distributed over the outer and inner surfaces of the hollow sphere.
No charge remains on the hollow sphere.
What is the process called where molecules in an uncharged object are caused to align in a particular direction due to an external charge?
Explain how an uncharged object can be attracted to a charged object. You should use diagrams to illustrate your answer.
Explain how a stream of water can be attracted to a charged rod.
An object has an excess charge of
. How many excess electrons does it have?
An object has an excess of 235 electrons. What is the charge on the object?
An object has an excess of 235 protons. What is the charge on the object?
Two identical, metal spheres have different charges. Sphere 1 has a charge of
. Sphere 2 has 60 excess electrons. If the two spheres are brought into contact and then separated, what charge will each have? How many electrons does this correspond to?
Two identical, insulated spheres have different charges. Sphere 1 has a charge of
. Sphere 2 has 60 excess electrons. If the two spheres are brought into contact and then separated, what charge will each have?
Two identical, metal spheres have different charges. Sphere 1 has a charge of
. Sphere 2 has 30 excess protons. If the two spheres are brought into contact and then separated, what charge will each have? How many electrons or protons does this correspond to?
Questions & Answers
A golfer on a fairway is 70 m away from the green, which sits below the level of the fairway by 20 m. If the golfer hits the ball at an angle of 40° with an initial speed of 20 m/s, how close to the green does she come?
A mouse of mass 200 g falls 100 m down a vertical mine shaft and lands at the bottom with a speed of 8.0 m/s. During its fall, how much work is done on the mouse by air resistance
Chemistry is a branch of science that deals with the study of matter,it composition,it structure and the changes it undergoes
Adjei
please, I'm a physics student and I need help in physics
Adjanou
chemistry could also be understood like the sexual attraction/repulsion of the male and female elements. the reaction varies depending on the energy differences of each given gender. + masculine -female.
Pedro
A ball is thrown straight up.it passes a 2.0m high window 7.50 m off the ground on it path up and takes 1.30 s to go past the window.what was the ball initial velocity
2. A sled plus passenger with total mass 50 kg is pulled 20 m across the snow (0.20) at constant velocity by a force directed 25° above the horizontal. Calculate (a) the work of the applied force, (b) the work of friction, and (c) the total work.
you have been hired as an espert witness in a court case involving an automobile accident. the accident involved car A of mass 1500kg which crashed into stationary car B of mass 1100kg. the driver of car A applied his brakes 15 m before he skidded and crashed into car B. after the collision, car A s
can someone explain to me, an ignorant high school student, why the trend of the graph doesn't follow the fact that the higher frequency a sound wave is, the more power it is, hence, making me think the phons output would follow this general trend?
Nevermind i just realied that the graph is the phons output for a person with normal hearing and not just the phons output of the sound waves power, I should read the entire thing next time
Joseph
Follow up question, does anyone know where I can find a graph that accuretly depicts the actual relative "power" output of sound over its frequency instead of just humans hearing
Joseph
"Generation of electrical energy from sound energy | IEEE Conference Publication | IEEE Xplore" ***ieeexplore.ieee.org/document/7150687?reload=true
A string is 3.00 m long with a mass of 5.00 g. The string is held taut with a tension of 500.00 N applied to the string. A pulse is sent down the string. How long does it take the pulse to travel the 3.00 m of the string?
