ch 3 & 4
Card Set Information
Author:
jb124
ID:
288830
Filename:
ch 3 & 4
Updated:
2014-11-10 19:23:27
Tags:
motion
Folders:
motion
Description:
motion
Show Answers:
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
slope = ?
speed
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 distance-time 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 X-axis
time
the further to the right, the ___
longer time
___ is always on the Y-axis
distance
the higher up the graph, the ___
further we are
what does a horizontal line on a distance-time 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 speed-time graph indicate?
constant speed
what is the Y-axis on a speed-time 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 speed-time graph be used to find the distance of an object?
speed x time
how can a speed-time graph be used to find the acceleration of an object?
speed/time
what is deceleration?
slowing down