AP Physics C: Mechanics Flashcards: Work
Written by AP Content Team, Verified for 2026 AP Exams, Last updated: May 2026
Review key ideas with interactive flashcards. This set includes 10 cards to help you master important concepts.
What is meant by 'net work' in the work-energy theorem?
Net work is the sum of the work done by all individual forces that are exerted on an object.
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What is meant by 'net work' in the work-energy theorem?
Net work is the sum of the work done by all individual forces that are exerted on an object.
What is work in the context of physics?
Work is the amount of energy transferred into or out of a system by a force exerted on that system over a distance.
How does work relate to a system's energy?
Work is the mechanism by which energy is transferred into or out of a system by a force.
What is the fundamental relationship between net work and change in kinetic energy?
The relationship is one of direct equality; the net work done on an object is precisely equal to the resulting change in the object's kinetic energy.
If the net work done on an object is positive, what happens to its kinetic energy?
According to the work-energy theorem, if the net work is positive, the object's change in kinetic energy is also positive, meaning it speeds up.
How is the work done by a variable force calculated?
The work done on an object by a variable force is calculated using the integral W = ∫ₐᵇ F⃗(r) ⋅ dr⃗.
State the equation for the work-energy theorem.
The equation for the work-energy theorem is ΔK = ΣWᵢ, where ΔK is the change in kinetic energy and ΣWᵢ is the net work.
What is the Work-Energy Theorem?
The work-energy theorem states that the change in an object's kinetic energy is equal to the sum of the work (net work) being done by all forces exerted on the object.
Why is an integral used to calculate the work done by a variable force?
An integral is used because it sums the infinitesimally small amounts of work (F⃗ ⋅ dr⃗) done over a path, accounting for changes in the force vector.
An object's kinetic energy decreases. What can be concluded about the net work done on it?
Based on the work-energy theorem (ΔK = ΣWᵢ), if an object's kinetic energy decreases, the change in kinetic energy (ΔK) is negative, so the net work done must be negative.