Electricity & MagnetismIntermediate

Coulomb's Law

Investigate Coulomb's law by observing electrostatic attraction/repulsion and the dependence of force on charges and distance.

Duration: 90 min

5 Topics

Electrostatic ForceElectric ChargesInverse Square LawCoulomb's ConstantData Analysis

Lab Details

Title: Lab1: Coulomb's Law

Level: Sophomore

Institution: SMU, MedTech, Mediterranean Institute of Technology

Term: Fall 2023 / Fall 2024

Learning Objectives

Verify proportionality of electrostatic force with product of charges
Verify inverse-square dependence with distance
Estimate Coulomb's constant from experimental slope
Compare measured and theoretical Coulomb constants

Interactive Simulation

Lab Assessment

Complete the following questions based on your observations from the simulation.

Table 1: Fixed Distance, Changing Charge

IV.1Table filling

Run experiment IV.1 and complete data results table.

Table 1: Fixed Distance, Changing Charge

*(8 points)

Run experiment IV.1 and complete data results table.

Record all measured values for fixed distance while varying charge.

Complete the table:

q1 (C)	q2 (C)	Distance r (m)	Force F21 (N)

Effect of Doubling $q_2$

IV.2.1Multiple Choice / Explanation

What happens to

F_{21}

when

q_2

is doubled while

q_1

is constant?

Effect of Doubling $q_2$

*(5 points)

What happens to

F_{21}

when

q_2

is doubled while

q_1

is constant?

Select answer and justify with data/theory.

Your Answer:

Effect of Reducing $q_1$ by Factor 3

IV.2.2Multiple Choice / Explanation

q_2

is constant and

q_1

is reduced by factor 3, what happens to

F_{21}

Effect of Reducing $q_1$ by Factor 3

*(5 points)

q_2

is constant and

q_1

is reduced by factor 3, what happens to

F_{21}

Provide justified conclusion from data.

Your Answer:

Table 2: Fixed Charge, Changing Distance

V.1Table filling

Run experiment V.1 and complete data results table.

Table 2: Fixed Charge, Changing Distance

*(8 points)

Run experiment V.1 and complete data results table.

Record values while varying distance with fixed charges.

Complete the table:

$q_1$ (C)	$q_2$ (C)	Distance $r$ (m)	$1/r^2$ ( $m^{-2}$ )	Force $F_{12}$ (N)

$F_e$ vs Distance Relationship

V.2.1Multiple Choice / Checkbox

Describe the relationship between electrostatic force

F_e

and distance

r

$F_e$ vs Distance Relationship

*(4 points)

Describe the relationship between electrostatic force

F_e

and distance

r

Support answer using Table 2 trends.

Your Answer:

Graph: $r$ vs $F_{12}$

V.2.2Graphing / Open-ended

Plot points

(X=r, Y=F_{12})

, add legend, and comment graph.

Graph: $r$ vs $F_{12}$

*(6 points)

Plot points

(X=r, Y=F_{12})

, add legend, and comment graph.

Use Table 2 columns 4 and 6 values.

Plot your data:

Electrostatic Force vs Distance

F_{12}

(N)

Left click: add point • Wheel: zoom • Right drag: pan

x: -, y: -

r

(m)

Graph: $1/r^2$ vs $F_{12}$

V.2.3Graphing / Open-ended

Plot points

(X=1/r^2, Y=F_{12})

, add legend, and comment graph.

Graph: $1/r^2$ vs $F_{12}$

*(6 points)

Plot points

(X=1/r^2, Y=F_{12})

, add legend, and comment graph.

Use Table 2 columns 5 and 6 values.

Plot your data:

Electrostatic Force vs Inverse-Square Distance

F_{12}

(N)

Left click: add point • Wheel: zoom • Right drag: pan

x: -, y: -

1/r^2

(

m^{-2}

)

Slope and Coulomb Constant

V.2.4Open-ended / Calculation

Measure the slope of the curve and deduce Coulomb constant

K_c

Slope and Coulomb Constant

*(7 points)

Measure the slope of the curve and deduce Coulomb constant

K_c

Show method and final value.

Your Answer:

$k_{meas}$ vs $k_{theo}$ Comparison

V.2.5Open-ended / Calculation

Compare experimental Coulomb constant with theoretical value and compute percent error.

$k_{meas}$ vs $k_{theo}$ Comparison

*(7 points)

Compare experimental Coulomb constant with theoretical value and compute percent error.

Provide numerical comparison and interpretation.

Your Answer:

Conclusion

ConclusionOpen-ended / Explanation

What did you learn from studying Coulomb's Law?

Conclusion

*(8 points)

What did you learn from studying Coulomb's Law?

Include: attractive/repulsive behavior, effect of distance, effect of charge, and Newton's third law.

Your Answer:

Lab Instructions

Explore the Interface

Familiarize yourself with the simulation controls and available parameters.

Experiment with Variables

Modify different parameters and observe how they affect the system behavior.

Record Observations

Take note of patterns, relationships, and any unexpected results.

Test Your Understanding

Try to predict outcomes before running experiments to test your comprehension.

Tips for Success

Start Simple

Begin with basic scenarios before exploring more complex situations.

Take Notes

Document your findings and any questions that arise during experimentation.

Repeat Experiments

Don't hesitate to repeat experiments with different parameters to verify results.

Ask Questions

Use unexpected results as learning opportunities to deepen your understanding.

Back to All Labs Complete Lab Evaluation

Coulomb's Law

Lab Details

Learning Objectives

Interactive Simulation

Lab Assessment

Table 1: Fixed Distance, Changing Charge

Table 1: Fixed Distance, Changing Charge

Effect of Doubling q2q_2q2​

Effect of Doubling q2q_2q2​

Effect of Reducing q1q_1q1​ by Factor 3

Effect of Reducing q1q_1q1​ by Factor 3

Table 2: Fixed Charge, Changing Distance

Table 2: Fixed Charge, Changing Distance

FeF_eFe​ vs Distance Relationship

FeF_eFe​ vs Distance Relationship

Graph: rrr vs F12F_{12}F12​

Graph: rrr vs F12F_{12}F12​

Graph: 1/r21/r^21/r2 vs F12F_{12}F12​

Graph: 1/r21/r^21/r2 vs F12F_{12}F12​

Slope and Coulomb Constant

Slope and Coulomb Constant

kmeask_{meas}kmeas​ vs ktheok_{theo}ktheo​ Comparison

kmeask_{meas}kmeas​ vs ktheok_{theo}ktheo​ Comparison

Conclusion

Conclusion

Lab Instructions

Explore the Interface

Experiment with Variables

Record Observations

Test Your Understanding

Tips for Success

Start Simple

Take Notes

Repeat Experiments

Ask Questions

Effect of Doubling $q_2$

Effect of Doubling $q_2$

Effect of Reducing $q_1$ by Factor 3

Effect of Reducing $q_1$ by Factor 3

$F_e$ vs Distance Relationship

$F_e$ vs Distance Relationship

Graph: $r$ vs $F_{12}$

Graph: $r$ vs $F_{12}$

Graph: $1/r^2$ vs $F_{12}$

Graph: $1/r^2$ vs $F_{12}$

$k_{meas}$ vs $k_{theo}$ Comparison

$k_{meas}$ vs $k_{theo}$ Comparison