Unit 1 Flashcards
Vector quantity
a physical quantity that has both magnitude and direction
Magnitude
the distance of a quantity from zero
Physical quantity
a property of a system that can be quantified by measurement
Direction
orientation or path of an object’s motion
Examples of vector quantities
displacement, velocity, momentum
System
collection of objects that are being studied together (e.g. sled and person on sled, single electron interacting with EM field)
Open system
Can exchange both matter and energy with surroundings (e.g. human body (waste and energy, such as food and oxygen, is transferred))
Closed system
Can exchange energy with surroundings but not matter (e.g. covered pot on stove with boiling water (heat can transfer but water cannot))
Isolated system
neither exchanges matter nor energy with surroundings (e.g. insulated water bottle (neither heat nor matter is exchanged with surroundings))
Force
when an object experiences a push or pull that causes a change in its motion. Force is a vector quantity, having both magnitude and direction
Equation for force
F=ma
-a: acceleration (m/s^2)
-m: mass (kg)
direction of acceleration is always same as direction of force
Gravitational force
force object experiences due to gravity, produces constant acceleration of 9.8 m/s toward surface of earth
Energy
the capacity to do work and exert force that causes and object to move or change its state, measured in Joules (J) (e.g. potential, kinetic, electrical, thermal, etc.)
Kinetic Energy (KE)
the energy of an object that is associated with its motion (e.g. throwing a ball, shooting arrow, falling, flying airplane) (never negative)
Formula for Kinetic Energy
KE=1/2mv^2
-m: mass (kg)
-v: velocity (m/s)
Potential Energy (PE or V)
the energy stored in an object due to its location relative to a specific reference point (e.g. raised object, dynamite, drawn bow, stretched spring, battery, etc.)