Work Flashcards
When is work done?
Work is done when a force moves an object through a distance
Work (J)= force (N) x distance (m)
What is energy?
Energy is the ability to do work - Joules
Conservation of energy?
Energy can be transformed from 1 type to another - cannot be created or destroyed
What is kinetic energy?
Energy solely by virtue of its motion
Ke (J) = 1/2mv^2
What is potential energy?
Stored energy - available to be transferred into work or another type of energy
Example of gravitational potential energy?
Pe = mgh
Changes in Pe?
Object rises - gains Pe
Change in Pe depends on h
Change in Pe = PeF - PeI
Conservation of mechanical energy?
Ke1 + Pe1 = Ke2 + Pe2 = E
Potential and kinetic energy may change but sum won’t
Velocity of falling object?
V =(2gh)^(1/2)
What is power?
Rate at which work is done, energy used
Power (W) = energy(J) / Time(s)
What is electrical energy usually recorded?
kWhr
What is food energy measured in?
calorie = 4.186 J
Kilocalorie/ Calorie = 4186J
