Unit 7: Work, Energy, Power Flashcards
Potential Energy
stored energy
Kinetic Energy
the energy of a moving object
energy
ability to do work
work
requires a release of energy, or force exerted through a distance
power
work completed/ time interval
when a force is perpendicular to the motion
no work is done
is work done when someone pushes a heavy box but it does not move?
no, a distance must be covered because of the force in order for work to occur
the more power you have the —– time it takes for work to occur
less
Mechanical Energy
potential and kinetic energy
what must remain conserved within a system
total amount of energy
Hookes Law
Force needed to stretch or compress a spring
x (springs)
distance spring is stretched from equilibrium position
If the direction of a moving car changes and its speed remains constant, what must remain the same?
kinetic energy
For work to occur:
the direction of motion is parallel to origin of the force
Consider the scenarios below. When is the weight-lifter doing WORK?
1. Lifting dumbbell from ground-level to waist-level
2. Holding dumbbell at waist level
3. Lifting dumbbell over head
4. Holding dumbbell over head
5. Lower dumbbell to waist-level
6. Lower dumbbell to ground-level
- WORK!
- NOT Work
- WORK!
- NOT Work
- NOT Work (Weight-lifter only controls RATE of GRAVITY)
- NOT Work (Weight-lifter only controls RATE of GRAVITY)
