Chapter 5 - Work, Energy, and Power Flashcards
What is work done?
Work is the energy transfer that takes place when a force causes an object to move
What is the formula for work done?
Work done = Force Applied x Distance moved in direct of force
What is energy?
Energy is the capacity of a body to do work
What is the law of conservation of energy?
Total energy in a closed system remains constant
Energy cannot be created or destroyed, only ever transferred form one form to another
What are the 9 forms of energy?
Kinetic
Gravitational Potential
Chemical
Elastic Potential
Electrical Potential
Nuclear
Sound
Internal (Heat/Thermal)
Radiant (EM)
What is kinetic energy?
Energy due to the motion of an object with mass
What is gravitational potential energy?
Energy of an object due to its position in a gravitational field
What is chemical energy?
Energy contained within the chemical bonds between atoms - it can be released when the atoms are rearranged
What is elastic potential energy?
Energy stored in an object as a result of reversible changes to its shape
What is electrical potential energy?
Energy of electrical charges due to their position in an electrical field
What is nuclear energy?
Energy within the nuclei of atoms - it can be released when the particles within the nucleus are arranged
What is sound energy?
Energy of mechanical waves due to the movement of atoms
What is internal (heat/thermal) energy?
The sum of the random potential and kinetic energies of atoms in a system
What is radiant (EM) energy?
Energy associated with all EM waves, stored within oscillating electric and magnetic fields
What is the formula for kinetic energy?
Ek = 1/2 x m x v2
What is the formula for gravitational potential energy?
Ep = m x g x h
What happens when a body falls and drag is ignored?
Ep = Ek
1/2 x m x v2 = m x g x h
What is the formula for power?
Power = Work Done / Time
What is the motion formula for power?
In a situation where a constant force is needed to maintain a constant speed
P = F x V
What is the formula for efficiency?
Efficiency = (Useful Output Energy / Total Input Energy) x 100
