Coulomb's Law Worksheet Answer Key: Quick Reference Guide
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Coulomb's Law is a fundamental principle in electrostatics, describing the force between two charged particles. Understanding this law is essential for students studying physics, as it provides a foundation for more complex topics in electromagnetism. In this quick reference guide, we will explore Coulomb's Law, its formula, applications, and provide a worksheet answer key to help reinforce these concepts.
What is Coulomb's Law?
Coulomb's Law states that the magnitude of the electrostatic force (F) between two point charges is directly proportional to the product of the magnitudes of the charges (q1 and q2) and inversely proportional to the square of the distance (r) between them. This is expressed mathematically as:
F = k * (|q1 * q2|) / r²
Where:
- F = electrostatic force (N)
- k = Coulomb's constant (8.99 × 10^9 N m²/C²)
- q1, q2 = magnitudes of the charges (C)
- r = distance between the centers of the two charges (m)
Key Concepts in Coulomb's Law
1. Nature of Charges
Charges can be either positive or negative. Like charges repel each other, while opposite charges attract. This interaction is fundamental to understanding how charged objects behave in an electric field.
2. Distance Matters
The distance between the charges plays a crucial role in determining the strength of the force. As the distance increases, the force decreases exponentially due to the square relationship in the denominator of Coulomb's Law.
3. Coulomb's Constant
Coulomb's constant (k) is a proportionality factor that makes the equation work in SI units. Remember that Coulomb's Law is applicable in a vacuum, and the value of k may change in different mediums.
4. Vector Nature of Forces
Coulomb's Law is a vector equation. The direction of the electrostatic force is along the line joining the two charges and is determined by the nature of the charges involved.
Coulomb's Law Worksheet
To reinforce your understanding of Coulomb's Law, we can provide a worksheet that allows you to practice calculating the forces between charged particles. Below is a set of sample questions along with an answer key.
Sample Questions
-
Calculate the force between two charges:
- q1 = +3 µC and q2 = -2 µC, separated by a distance of 0.5 m.
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Determine the electrostatic force between two charges:
- q1 = +5 µC and q2 = +5 µC, separated by a distance of 0.2 m.
-
If one charge is doubled, how does the force change?
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What happens to the force if the distance is tripled?
Answer Key
Here are the answers to the above questions:
<table> <tr> <th>Question</th> <th>Answer</th> </tr> <tr> <td>1. F = k * (|q1 * q2|) / r²</br></td> <td>F = (8.99 × 10^9) * (|3 × 10^-6 * -2 × 10^-6|) / (0.5)² = 0.1074 N</td> </tr> <tr> <td>2. F = k * (|q1 * q2|) / r²</br></td> <td>F = (8.99 × 10^9) * (|5 × 10^-6 * 5 × 10^-6|) / (0.2)² = 112.36 N</td> </tr> <tr> <td>3. If q2 is doubled, then F doubles as well (F ∝ q).</td> </tr> <tr> <td>4. If the distance is tripled (r = 3r), then F decreases to 1/9 of the original force (F ∝ 1/r²).</td> </tr> </table>
Applications of Coulomb's Law
Understanding Coulomb's Law is vital for various applications in physics and engineering. Here are some significant applications:
1. Electrostatic Forces
In everyday life, electrostatic forces play a role in phenomena such as static cling and the behavior of charged objects.
2. Physics Experiments
Coulomb's Law is often used in laboratory settings to investigate the forces between charged particles, providing hands-on experience for students.
3. Electromagnetic Theory
Coulomb's Law lays the groundwork for concepts in electromagnetic theory, leading to the development of Maxwell’s equations.
4. Technology Development
Understanding electrostatic forces is crucial in fields like semiconductor technology and electronics, influencing the design of transistors and capacitors.
Important Notes
- When solving problems related to Coulomb's Law, always pay attention to the signs of the charges, as they determine the nature (attractive or repulsive) of the force.
- Ensure units are consistent (charges in Coulombs, distances in meters) to avoid errors in calculations.
Coulomb's Law is an essential concept that every physics student should grasp, as it not only helps in solving problems related to electrostatics but also forms a foundation for further studies in electricity and magnetism. By practicing with the provided worksheet and understanding the underlying principles, students can develop a robust comprehension of electrostatic forces.