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what is Newton's first law of motion?
an object at rest will remain at rest and an object in motion will continue moving at a constant velocity unless acted upon by a net force

change in position in relation to a reference point
motion

speed
 rate of motion
 distance traveled per unit of time

calculation of speed
speed = distance/time

Sound travels 330 m/s. If a lightning bolt strikes the ground 1 m away from you, how long will it take for you to hear it?
330 s

Your friend skates at a speed of 4 m/s. You can skate 100 m in 20 s. Who skates faster?
you do

speed at a given instant
instantaneous speed

average speed equals?
total distance/total time

speed that doesn't change over time
constant speed

speed that is not constant
changing speed

speed in a given direction
velocity

can velocity change even when the speed is constant?
yes

distance and direction of an object's change of position from a starting point
displacement

a runner runs a distance of 50 m in one direction and then 30 m in the opposite
displacement = ?
20 m

acceleration
 the rate of change of velocity
 change in speed or direction

positive acceleration
speeding up

negative acceleration
slowing down

A roller coaster starts down a hill at 10 m/s. Three seconds later, its speed is 32 m/s. What is the roller coaster's acceleration?
7.3 m/s^{2}

how long will it take a car traveling 30 m/s to come to a stop if its acceleration is 3 m/s^{2}?
10 s


straight line on a graph?
constant speed

flat line on a graph?
no motion

steeper slope on a graph?
faster speed

how is acceleration indicated on a distancetime graph?
by a curve

changing slope = ?
changing velocity

acceleration occurs when an object's ___ changes
speed

when an object speeds up, it has ___ acceleration
positive

when an object's final velocity is less than its initial velocity, it has ___ velocity
negative

formula for acceleration?
A = Vf  Vi /T

___ is always on the Xaxis
time

the further to the right, the ___
longer time

___ is always on the Yaxis
distance

the higher up the graph, the ___
further we are

what does a horizontal line on a distancetime graph indicate?
something isn't moving

what does a straight line with a positive slope indicate?
steady speed

when the motion of 2 objects is plotted on the same graph, how can you tell which one has the greater speed?
steeper incline

how do you tell if the speed of an object is constant?
constant gradient

what does the horizontal line on a speedtime graph indicate?
constant speed

what is the Yaxis on a speedtime graph?
speed

what does a straight line with a positive slope indicate?
acceleration

what does a straight line with a negative slope indicate?
acceleration

when the speed of 2 objects is plotted on the same graph, how can you tell which one has the greater acceleration?
steeper gradient

how can a speedtime graph be used to find the distance of an object?
speed x time

how can a speedtime graph be used to find the acceleration of an object?
speed/time

what is deceleration?
slowing down