Questions and Answers
What is energy?
What is work?
Work is a force applied for a distance, in the same direction as the distance.
What is the equation for work?
W=Fdcos(theta)
What does theta equal when there is no work being done?
Signup and view all the answers
When is work considered done?
Signup and view all the answers
Work is a vector quantity that can be positive or negative.
Signup and view all the answers
What determines the stiffness of a spring according to Hooke's law?
Signup and view all the answers
What is Hooke's law equation?
Signup and view all the answers
What does kinetic energy depend on?
Signup and view all the answers
What is the equation for gravitational potential energy?
Signup and view all the answers
What is the formula for elastic potential energy?
Signup and view all the answers
What is the W-KE theorem?
Signup and view all the answers
What is power?
Signup and view all the answers
What does the conservation of energy principle state?
Signup and view all the answers
Study Notes
Energy and Work
- Energy is the capacity to perform work.
- Work occurs when a force is applied over a distance, requiring direction alignment between force and distance.
- Work is quantified by the formula: W = Fd cos(theta), measured in joules (Newton * meter).
Angle Considerations in Work
- When θ = 0: cos(0) = 1; work is maximized as the object moves positively.
- At θ = 90 degrees: cos(90) = 0; no work is performed.
- If θ > 90 degrees: work is negative, indicating opposing direction.
- If θ < 90 degrees, work is positive; total work can be calculated as w_net, the sum of all forces.
Characteristics of Work
- Work is only performed when force components are parallel to displacement.
- It is a scalar quantity, which can be positive or negative based on force direction relative to displacement.
- Positive net work accelerates the object, while negative net work results in deceleration.
Hooke's Law and Springs
- Hooke's Law focuses on spring mechanics, governed by force, stiffness, and spring constant (k, N/m).
- The equation for Hooke's Law is F = kx, where k indicates stiffness, and x represents elongation or compression.
Energy Types
- Kinetic Energy (KE) depends on mass and velocity, defined as KE = 1/2 mv² (measured in joules).
- Gravitational Potential Energy (PEg) relies on mass, height, and gravity, expressed as PEg = mgh.
- Elastic Potential Energy is given by PE elastic = 1/2 kx², based on spring stiffness and compression/stretch distance.
Energy Conservation
- The principle of conservation of energy states that total mechanical energy (KE + PE) remains constant in a closed system without friction.
- The relationship between net work and kinetic energy is expressed as W - KE Theorem: net work equals change in kinetic energy.
Power
- Power quantifies the rate at which work is accomplished, defined as P = W/t (watts = joules/second).
- An alternate formula for power is P = Fv, combining force and velocity for calculations.
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
Description
These flashcards cover fundamental concepts of work, energy, and power. Learn key definitions and important equations that describe the relationship between these physical quantities. Ideal for students looking to reinforce their understanding of physics.
