Describing Motion
speed that does not vary
constant speed
when you know both the speed and direction of an object's motion, you know the _________
velocity
pushing an elephant is an example of what type of friction
static friction
the tendency of an object to resist change in its motion is known as _____
inertia
an astronaut on the moon would have the same _____ as on Earth
mass
air resistance is a type of ______
friction
speed equals distance divided by _____
time
acceleration is the rate of change in ________
speed
the force that one surface exerts on another when the two rub against each other is called ______
friction
according to Newton's second law of motion, ______ depends on an object's mass and the net force acting on the object
acceleration
any force that causes an object to move in a circle is called a __________
centripetal force
Newton's 3rd law states that for every action there is an equal and opposite _________
reaction
total distance traveled divided by the total time is _____ speed
average
a golf ball _______ when either its speed or direction changes
accelerates
balanced forces acting on an object will have what effect on the object?
never change the object's motion
if the action of a bat striking a ball accelerates the ball in one direction, the reaction force accelerates the bat in the _______ direction
opposite
an object that is thrown
projectile
the rate at which an object is moving at a given instant
instantaneous speed
occurs when an object changes position relative to a reference point
motion
state the acceleration formula
(final velocity - initial velocity) divided by time OR change in velocity divided by time
_________ is when 2 or more forces act on an object at the same time
net force
Paddling a canoe and the canoe moving forward is an example of which law
newton's 3rd law
gravitational force exerted on an object is called ____
weight
the path of a projectile is curved; the horizontal velocity is due to __________
inertia or newton's 1st law
distance and direction of an object's change in position from its starting point
displacement
a plane taking off is an example of ________
positive acceleration
microscopic bumps on a surface
microwelds
formula for Newton's 2nd Law
Force is equal to mass times acceleration OR
F = m * a
mass of the objects AND the distance between the objects
the greater the mass of an object, the greater its _____________
inertia