Physics Flashcards
Force
a push or pull
- causes objects to change speed or directions
- object only accelerates when forces are unbalanced
- forces are represented by arrows
- size of arrow = strength of force
- direction of arrow = direction of force
Force Diagrams
- gravity is always down
- normal force is perpendicular to the surface
- net force is all forces added together
- shows the direction of acceleration
- friction is opposite the direction of motion
Friction
a force that opposes motion
- caused by rough surfaces of all materials
- friction results in heat
- effects of friction
- spinning
- curving
- slowing
4 Types of Friction
- sliding - when solid objects grind over each other
- rolling - turning over and over on an axis
- fluid - when liquids or gas slow the motion of a solid
- static - the friction between two solids that aren’t moving
Newton’s 1st Law
an object in motions tends to stay in motion and an object at rest tends to stay at rest until acted on by an outside force
Inertia
a property of matter that resists a change in motion
-objects with great mass have high inertia
Newton’s 2nd Law
unbalanced forces make objects accelerate
force = mass x acceleration
Newtons 3rd Law
for every action there is an equal and opposite reaction
Energy
the ability to do work
Mechanical Energy
energy related to motion
- PE + KE = Mechanical Energy
Potential Energy
stored energy that can be released to do work
Chemical Energy
the energy required to bond atoms together
- building bonds uses energy
- breaking bonds releases energy
Elastic Potential Energy
energy associated with objects that can be stretched or compressed
Work
- transfer of energy
- power = rate at which work is done
Kinetic Energy
energy an object has due to its motion
-depends on mass and velocity
Gravitational Potential Energy
energy that’s stored in objects that are high off the ground
Thermal Energy
the internal motion of atoms
- rapid motion - high energy
- slow motion - low energy
Electromagnetic Energy
the energy of moving electric charges
- electricity
- infrared and ultraviolet radiation
- (sun)light
- radio waves
Nuclear Energy
the energy that is created by building or breaking the nuclei of atoms
- creates lots of heat
- stored in nucleus
- released during nuclear reactions
Fission
breaking nuclei into smaller atoms
-means “to cut”
Law of Conservation of Energy
energy cannot be created or destroyed, only changed from one form to another
Electrical Energy
energy of electric charges
-can be either PE or KE
Single Transformations
one form of energy being transformed to get work done
Multiple Transformations
a series of energies being transformed to get work done
Energy Relationships
- Friction and Energy
friction transforms mechanical energy to thermal energy - Energy and Matter
matter can be transformed to energy
Acceleration
a change in velocity
