Forces and Motion Unit Test Flashcards
What is a reference point?
a direction relative to an object in motion
what are the two factors that determine an object’s speed?
distance and time (distance/time)
what is velocity?
speed in a particular direction
how is acceleration calculated?
difference in velocity/difference in time
how do you combine forces in opposite same directions?
opposite- subtract smaller from the larger
same- add them together
what can an unbalanced force do to an object’s motion?
make it start moving or change the object’s motion
what is friction
a common force that opposes motion between two moving objects
how can you determine if the forces on an object are balanced or unbalanced?
balanced forces have a net force of 0 newtons, unbalanced forces don’t
define mass
a measure of the amount of matter in an object
define weight
measure of the amount of gravitational force on an object
how are mass and weight calculated?
mass is calculated using a balance and weight is calculated using a spring scale
why do all objects fall at the same rate?
acceleration due to gravity is the same for all objects
what is the rate for acceleration due to gravity
9.8 m/s (2)
what factors determine how much gravitational force there is between objects
distance and mass
what is projectile motion
the curved path an object follows when thrown or launched
what forces act on falling objects
gravity and air resistance
what is newtons first law
an object at rest/motion tends to stay in rest/motion unless acted upon by an unbalanced force
define inertia
the tendency of all objects to resist any changes in motion
what is newtons second law
force=mass x acceleration
what is newtons third law
when one object exerts a force on a second object, the second exerts an equal and opposite force on the first
what is momentum
mass x velocity
what does the law of conservation of momentum state
during a collision, the amount of momentum always remains the same
what is a fluid,
a nonsolid state of matter in which the molecules are free to move past each other
what is atmospheric pressure
the pressure caused by the weight of the atmosphere
what is water pressure
the pressure caused when under water at a certain depth
how do fluids move?
the molecules move freely past each other
define archimedes principle
the buoyant force on an object in a fluid is an upward force equal to the weight of the volume of the fluid that the object displaces
define bernoullis principle
pressure in a fluid decreases as the fuids velocity increases
what is lift
upward force on an object that moves in a fluid
define pascals principle
a fluid in equilibrium contained in a vessel exerts a pressure of equal intensity in all directions
