Physics net charge homework help

In summary, the conversation includes calculations of net charge, electrostatic force, electric field, potential energy, and kinetic energy in various scenarios involving charges and electric fields. It also includes a question about the equivalence of units and a request for the calculation process to be shown.
  • #1
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I've been behind in class. It'd really be helpful if anyone could help me. It's hard, but if you know it, just help me, please. Here it is:
1) Calculate the net charge on a substance consisting of (a) 5 x 10^14 electrons and (b) a combination of 7 x 10^13 protons and 4 x 10^13 electrons.

2) Two identical conducting spheres are placed a distance of 0.3 m between their centers. One is given a charge of 12 x 10^-9 C and the other a charge of -18 x 10^-9 C. (a) Find the electrostatic force exerted on one sphere by the other. (b) The spheres are now connected by a conducting wire. After equilibrium has occurred, find the electrostatic force between the two.

3) The electric force on a point charge of 5 x 10^-9 C at some point is 3.8 x 10^-3 N in the positive X direction. What is the magnitude of the electric field at this location?

4) What are the magnitude and direction of the electric field setup by the proton at the position of the electron in the hydrogen atom?

5) The electrons in a particle beam each have a kinetic energy of 1.6 x 10^-17 J. What are the magnitude and direction of the electric field that will stop these electrons in a distance of 10cm?

6) A proton accelerates from rest in a uniform electric field of 640 N/C. At some later time, its speed is 1.20 x 10^6 m/s. (a) Find the acceleration of the proton. (b) How long does it take the proton to reach this velocity? (c)How far has it moved in this time? (d) What is its kinetic energy at this time?

7) (a) How much work is done by a uniform electric field 200 N/C as the charge moves a distance of 2 cm in the field? (b) What's the difference in potential energy between these two points?

8) Show that units N/C and V/m are equivalent.

9) The difference in potential energy between the accelerating plates of a TV set is about 25,000 V. If the distance between these plates is 1.5 cm, find the magnitude of the uniform electric field in this region.

10) (a) What potential difference is needed to stop an electron with an initial speed of 4.2 x 10^5 m/s? (b)How much energy does this require?

11) At what distance from a point charge of 6 microcoulombs would the potential equal 27,000 V?

12) Calculate the speed of (a) an electron that has a kinetic energy of lev, and (b) a proton that has a kinetic energy of 1eV.

13) How much energy is gained by a charge of 75 microcoulombs moving through a potential difference of 90V? Express your answer in (a) joules and (b) electronvolts.
 
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  • #2
How about showing your work first?
 
  • #3


Sure, I'd be happy to help you with your physics net charge homework. It's completely understandable to fall behind in class, so don't worry, we'll work through these problems together.

1) To calculate the net charge, we need to add the charges of the electrons and protons together. For (a), the net charge would be -5 x 10^14 electrons. For (b), the net charge would be 3 x 10^13 electrons (7 x 10^13 protons + 4 x 10^13 electrons).

2) (a) To find the electrostatic force, we can use Coulomb's Law: F = k(q1q2)/r^2. Plugging in the values, we get F = 8.99 x 10^9 * (12 x 10^-9 * (-18 x 10^-9)) / (0.3)^2 = -2.39 x 10^-3 N. The negative sign means the force is attractive.

(b) When the spheres are connected by a conducting wire, they will reach equilibrium and have the same charge. This means the force between them will be 0.

3) We can use the equation F = qE to find the electric field. Plugging in the values, we get E = F/q = (3.8 x 10^-3 N) / (5 x 10^-9 C) = 7.6 x 10^5 N/C.

4) The electric field created by the proton at the position of the electron in a hydrogen atom would be the same as the field in problem 3, since the proton has the same charge as the electron in magnitude but opposite in sign. The direction of the field would be towards the proton.

5) We can use the equation F = qE to find the electric field. First, we need to find the charge of each electron by using the kinetic energy formula KE = (1/2)mv^2. Plugging in the values, we get q = (2 * 1.6 x 10^-17 J) / (4.8 x 10^5 m/s)^2 = 6.67 x 10^-19 C. Now, we can solve for the electric field: E = F/q = (1.6 x 10^-17 J / 0.1 m) / (6.67
 

FAQ: Physics net charge homework help

What is net charge in physics?

Net charge in physics refers to the overall charge of an object or system, taking into account the positive and negative charges present. It is typically measured in units of Coulombs (C) and can be either positive, negative, or neutral.

How is net charge calculated?

To calculate net charge, you need to consider the number of positive and negative charges present. If an object has more positive charges than negative charges, it will have a positive net charge. Conversely, if it has more negative charges than positive charges, it will have a negative net charge. If the number of positive and negative charges is equal, the object will have a neutral net charge.

Why is net charge important in physics?

Net charge is important in physics because it helps us understand how objects interact with each other. Charged objects can either attract or repel each other, and the strength of this interaction is determined by their net charges. Additionally, net charge is a fundamental property that can be used to explain various phenomena, such as electricity and magnetism.

What is the conservation of net charge?

The conservation of net charge is a fundamental law in physics that states that the total amount of net charge in a closed system remains constant over time. This means that net charge cannot be created or destroyed, only transferred from one object to another. This law helps us understand the behavior of charged objects and their interactions with each other.

How is net charge related to electric fields?

Net charge is directly related to electric fields. Electric fields are created by charged objects, and the strength of the electric field is determined by the net charge of the object. The direction of the electric field is also determined by the net charge, with positive charges creating outward-pointing fields and negative charges creating inward-pointing fields. Electric fields play a crucial role in many physics phenomena, such as electricity, magnetism, and electromagnetic radiation.

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