Chapter 4: Work and Energy Flashcards
Equation for work
W=f*d
Equation for power
P=w/t
Unit of work
Joule (J)
Unit of power
Watt
A Joule (J) can be written as…
Nm
Kgm/s^2m
Kgm^2/s^2
Common misconception about machines…
Machines don’t do more work, they just decrease the amount of force you apply
Equation for Mechanical Advantage
MA=F in/F out
Equation for Ideal Machines
F ind in=F outd out
Unit for Mechanical Advantage
There is none
Equation for Efficiency
Eff=w out/w in*100
Definition of work
When a force (a push or pull) is applied to an object and the object moves.
It it work if someone is carrying something?
No
Energy is…
The ability to cause change
Types of energy
Light
Thermal
Electrical
Sound
Nuclear
Mechanical (KE and PE)
Kinetic energy is…
Energy due to an objects motion
Kinetic energy depends on
Mass and speed of object
Potential energy is…
Stored energy
Types of potential energy
Elastic (EPE)
Chemical (CPE)
Gravitational (GPE)
Equation for gravitational potential energy (GPE)
GPE=mah
What is the law of conservation of energy?
Energy can’t be created nor destroyed, but can be transferred in different forms
Mechanical energy is…
The total amount of energy in a system
Equation for mechanical energy (ME)
ME=KE+PE
T or F: Work and energy are related
True
Equation for kinetic energy (KE)
KE=0.5m*v^2
