physics semester test Flashcards
a description of how close a measurement is to the correct or accepted value of the quantity measured
accuracy
the degrees of exactness of a measurement
precision
are those digits in a measurement that are known with certainty plus the first digits that is uncertain
significant digits
a change in position of an object
displacement
the total displacement divided by the time interval during which the displacement occurred
average velocity
the rate at which velocity changes over time; an object accelerates if this speed, direction, or both change
acceleration
the motion of a body when only the force due to gravity is acting on the body
free fall
is a physical quantity that has both magnitude and direction
vector
is the curved path that an object follows when thrown, launched or otherwise projected near the surface of earth
projectiles motion
an action exerted on an object which may change the object’s state of rest or motion; has magnitude and direction
force
is the tendency of an object to resist being moved, or if the object is moving, to resist a change in speed or direction
inertia
a single force whose external effects in a rigid body are the same as the effects of several actual forces action on the body
net force
is the state in which the net force on an object is zero
equilibrium
an object at rest remains at rest, and an object in motion continues in motion with constant velocity ( this is constant speed in a straight line) unless the object experiences a net external force
Newton’s first law
the acceleration of an object is directly proportional to the net force action on the object and inversely proportional to the object’s mass
Newton’s second law
for every action, there is an equal and opposite reaction
Newton’s third law
a measurement of the gravitational force exerted on an object; its value can change with the location of the object in the universe
weight
a force that acts on a surface in a direction perpendicular to the surface
normal force
the force that resists the initiation of sliding motion between two surfaces that are in contact and at rest
static friction
the force that opposes the movement of two surfaces that are in contact and are sliding over each other
kinetic friction
the ratio of the magnitude of the force of friction between two objects in contact to the magnitude of the normal force with which the objects press against each other
coefficient of friction
1 kg*m/s^2
newton
the projections of a vector along the axes of a coordinate system
components of a vector
anything is change
delta
meter per second
velocity
meters per second squared
acceleration
N, Newton
force
