88 terms

# Combo with "Final Exam Semester 2 Physical Science" and 2 others

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Force
a push or pull causing an object to start or stop moving or change its motion
Friction
the force that opposes the motion of an object
Sliding Friction
when two solid surfaces slide over eachother
Rolling Friction
when an object rolls over a surface
Fluid Friction
when an object moves through a fluid
Lubricant
substances that enable sliding friction to change to fluid friction
Balanced Forces
forces that are opposite in direction and equal in size (no change in motion)
Unbalanced Forces
forces that are not opposite in direction and equal in size (one force is greater than the other=change in motion)
Inertia
tendency of objects to remain in motion or stay at rest
First Law of Motion
on object at rest will stay at rest and an object in motion will remain in motion unless acted upon by an unbalanced force
Second Law of Motion
relationship between force, mass and acceleration (force=mass x acceleration)
Third Law of Motion
for every action there is an equal and opposite reaction
Gravity
the attractive force between all objects in the universe
9.8m/s/s
acceleration rate due to gravity
Projectile Motion
always a curve, the path a projectile takes when thrown into the air (forward due to inertia and downward due to gravity)
Orbital Motion
An object that orbits another object
Law of Universal Gravitation
all objects in the universe attract each other by the force of gravity
Weight
the measure of the force of gravity on a mass, measured in Newtons (weight may vary)
Mass
the amount of matter that makes up an object (this remains constant)
Energy
the ability to do work
Joule
one unit of energy
Mechanical Energy
energy associated with motion
Heat Energy
the internal motion of particles of matter; often causes changes in temperature
Chemical Energy
the energy that bonds atoms or ions together
Electromagnetic Energy
Moving electric charges; is included in X-rays, radio waves and laser light
Nuclear Energy
When a nucleus splits, this type of energy is released; most concentrated form of energy
Potential Energy
energy stored in an object due to its position
Kinetic Energy
energy that a moving object has due to its motion
Gravitational Potential Energy
energy that is dependent on height above the earth's surface
Energy Conversions
changes in forms of energy
Heat Engine
machines that change heat energy into mechanical energy
Work
a force acting through a distance
ForcexDistance=
Work
One Newton-meter is equal to
a Joule
Power
rate at which work is done, or the amount of work done per unit of time
Work/Time=
Power
Large quantities of power are measured in
Kilowatts
One joule/second is known as a
Watt
750 watts equals
one Horsepower
This makes work easier
a machine
Effort force
Force applied to the machine
Work done on a machine is
Work Input
Force applied by the machine
Resistance Force
Work done by a machine
Work Output
the number of times a machine multiplies the effort force
Efficiency
The comparison of work output to work input
A slanted surface used to raise an object
Inclined plane
An inclined plane that moves (most are made of two inclined planes)
Wedge
An inclined plane wrapped around a cylinder to form a spiral
Screw
A bar that is free to pivot or move about a fixed point when an effort force is applied
Lever
The fixed point on a lever
Fulcrum
___________ class levers multiply the effort force and change its direction. Fulcrum is between Resistance force and Effort Force
First
___________ class levers have the Resistance force between the Fulcrum and the Effort force
Second
___________ class levers have the Effort force between the Resistance force and the Fulcrum. Effort force is greater than the resistance force and the lever multiplies the distance of the effort force.
Third
Pulley
A chain, belt or rope wrapped around a wheel. This may change the direction or the amount of the effort force.
A lever that rotates in a circle
Wheel and Axle
Compound Machine
a combination of two or more simple machines
Frame of Reference
Point or object from which movement is determined
Earth
Most common frame of reference
Motion
Change in position relative to a frame of reference
Speed
Distance traveled per unit of time
Constant Speed
Speed that does not change
Average speed
Speed that changes; not constant
Velocity
Speed in a given direction
Acceleration
Rate of change in velocity
Deceleration
A decrease in velocity
Centripetal Acceleration
Acceleration directed toward the center of the circular path
Momentum
Mass multiplied by its velocity
Law of Conservation of Momentum
Total momentum of any group of objects remains the same unless acted upon by outside forces
Force
a push or pull causing an object to start or stop moving or change its motion
Friction
the force that opposes the motion of an object
Sliding Friction
when two solid surfaces slide over eachother
Rolling Friction
when an object rolls over a surface
Fluid Friction
when an object moves through a fluid
Lubricant
substances that enable sliding friction to change to fluid friction
Balanced Forces
forces that are opposite in direction and equal in size (no change in motion)
Unbalanced Forces
forces that are not opposite in direction and equal in size (one force is greater than the other=change in motion)
Inertia
tendency of objects to remain in motion or stay at rest
First Law of Motion
on object at rest will stay at rest and an object in motion will remain in motion unless acted upon by an unbalanced force
Second Law of Motion
relationship between force, mass and acceleration (force=mass x acceleration)
Third Law of Motion
for every action there is an equal and opposite reaction
Gravity
the attractive force between all objects in the universe
9.8m/s/s
acceleration rate due to gravity
Projectile Motion
always a curve, the path a projectile takes when thrown into the air (forward due to inertia and downward due to gravity)
Orbital Motion
An object that orbits another object
Law of Universal Gravitation
all objects in the universe attract each other by the force of gravity
Weight
the measure of the force of gravity on a mass, measured in Newtons (weight may vary)
Mass
the amount of matter that makes up an object (this remains constant)