Goals
1. Recognise that electric force is capable of doing work.
2. Utilise the concept of work done by electric force to determine the value of an electric charge.
3. Apply the work done by electric force in calculating speeds.
4. Make connections between work and energy within the context of electric force.
5. Enhance problem-solving skills related to electricity.
Contextualization
Electricity plays a vital role in our everyday lives, integral to everything from the functioning of our gadgets to the lighting in our homes. A grasp of the work done by electric force is essential not only for understanding how these devices operate but also for innovating and improving existing technologies. This understanding lays the groundwork for numerous technical and scientific careers, including electrical engineering, electronics, and even fields like medicine, where tools such as defibrillators harness electrical principles to save lives. Take electric vehicles as an example; here, electrical energy is converted into mechanical work to facilitate movement, while in the electronics sector, a solid understanding of electric force is crucial for designing and managing circuits in devices like smartphones and computers.
Subject Relevance
To Remember!
Work Done by Electric Force
The work done by electric force indicates how much energy is transferred or changed when an electric force moves an electric charge through an electric field. This is a core idea for grasping how electricity enables work across different devices.
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Work is calculated using the formula W = F * d * cos(θ), where W represents work, F is force, d is distance, and θ is the angle between the force and the direction of motion.
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In an electric field, work can be expressed as W = q * E * d, where q represents electric charge, E indicates the strength of the electric field, and d is the distance travelled.
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The work done by electric force is measured in joules (J).
Relationship between Electric Force, Charge, and Displacement
Electric force is the force exerted on an electric charge due to the electric field's presence. This force can displace the charge, effectively doing work. The strength of this force hinges on both the charge's value and the electric field's intensity.
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Electric force can be expressed by the formula F = q * E, where F is force, q is electric charge, and E is the intensity of the electric field.
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The displacement of a charge influenced by an electric force results in work performed by the electric field.
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The direction of the electric force is shaped by the charge's polarity and the orientation of the electric field.
Calculating Work Done by an Electric Force
To compute the work done by an electric force, one must know the electric charge, the electric field's intensity, and the distance the charge moves. This calculation is fundamental for comprehending how electricity transforms into other energy forms.
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The foundational formula is W = q * E * d, where W represents work, q is electric charge, E is the electric field's intensity, and d is the distance traversed.
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Calculating work is crucial for the design and analysis of electrical devices, like motors and generators.
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Understanding the work done by electric force aids in optimising energy usage in electrical and electronic systems.
Practical Applications
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In electric motors, electric force performs work by changing electrical energy into mechanical energy to move the motor's components.
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Defibrillators use electric force to restore a normal heart rhythm by applying a controlled electric shock to the heart.
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Renewable energy systems, such as solar panels and wind turbines, rely on transforming electrical energy to provide clean and sustainable power.
Key Terms
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Electric Force: The force one electric charge exerts on another charge within an electric field.
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Work: The energy transferred or converted by a force when moving an object over a distance.
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Electric Charge: The physical property of matter that generates a force when placed in an electric field.
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Electric Field: The area surrounding an electric charge where other charges experience a force.
Questions for Reflections
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How might understanding the work done by electric force contribute to creating sustainable technologies?
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In what ways can knowledge of electric force and work be used in medical engineering?
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Why is optimising the use of electrical energy important in everyday electronic devices?
Practical Challenge: Measuring the Work Done by Electric Force
Reinforce your understanding of the work done by electric force with this practical challenge, where you will quantify the amount of work done when moving an electric charge in an electric field.
Instructions
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Gather the necessary materials: a ruler, a power source (battery), copper wire, a small charge (like a piece of aluminium or copper), and a voltmeter.
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Create a simple circuit to measure the voltage (V) and the current (I) passing through the copper wire.
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Measure the distance (d) the charge moves along the copper wire.
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Use the formula W = V * I * t to calculate the work (W) done by the electric force, where t is the time taken during the charge's displacement.
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Document your observations and compare your findings with the theoretical concepts we've discussed in class.
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Consider how this experiment illustrates the work done by electric force in practical terms.
