51 terms

# Chapter 1 Motion and Momentum

#### Terms in this set (...)

speed
rate of change of position, which can be calculated by diving the distance traveled by the time it take tot travel that distance
Speed = Distance divided by time
average speed
Average speed is found by dividing the total distance traveled by the time taken
instantaneous speed
the speed of an object at one instant of time
velocity
the speed of the object and direction of its motion
accleration
rate of change of velocity; can cause an object to speed up, slow down, or turn, and can be calculated by the change in velocity divided by the time it takes for the change to occurs
mass
is the amount of matter in the object. In SI units the unit for mass is the kilogram
inertia
tendency of an object to resist a change in its motion
momentum
is a measure of how hard it is to stop the object
momentum = mass times velocity or p=mv
law of conservation of momentum
the total momentum of objects that collide with each other is the same before and after the collision
What is true about all matter in the universe?
it is constantly in motion
Define when something is in motion
is is changing in position
What do you need to determine whether something has changed position
a point of reference
what is distance
how far you or an object has moved
Define displacement
it is the direction and difference in position between your starting point and your ending
What is speed
Speed is the distance traveled divided by the time taken to travel the distance
Formula for speed is
Speed = distance/time
What is the speed of 100 meters in 10 seconds
10 meters/second
What is average speed?
divide total distance traveled by time taken
What do you know about object in motion and its speed?
an object in motion can change speeds many times as object speeds up or slows down
Instantaneous speed
the speed of an object at one instant of time
What is one way that you can view two objects traveling at different speeds
by plotting data on a graph
Velocity
defined as the speed of an object and direction of its motion
What is acceleration
change in velocity divided by the time it takes for the change to occur
What is true about velocity and acceleration
they both have a direction
If an object speeds up in which direction is the acceleration
the acceleration is in the direction that the object is moving
What happens if the direction of the acceleration is at an angle to the direction of motion?
the direction of motion will turn toward the direction of acceleration
If an object slows down in which direction is the acceleration
the acceleration is in the opposite direction that the object is moving
What can you say about an object whose speed is increasing
the object is accelerating
When the speed is decreasing what can you say about the direction of acceleration
the direction of acceleration is opposite to the direction of motion
Acceleration is
(Final speed minus initial speed) divided by time
What is the formula for acceleration
(Sf-Si)/t
If the acceleration formula is positive what do you know about the object
the object is speeding up in the direction of the motion
If the acceleration formula is negative what do you know about the object
the object is speeding up in the opposite direction of motion
If you graph an acceleration line, what do the x axis and what is the y axis represetn
x axis is time; y axis is speed
if the acceleration line has a positive slope what do you know
the object is speeding up
if the acceleration line has a negative slope what do you know
the object is slowing down
How do you know if an object has changed position?
an object has changed position if it moves relative to a reference point
What two different things does a horizontal line represent on a speed-time graph
an acceleration of zero OR constant speed
when is an object in motion
if it is changing position
Define distance
distance measures the length of the path that an object follows during its motion
What is displacement?
displacement is the change in position between the starting point and the ending point AND the direction from the start to end points
what is speed?
Speed equals distance divided by time
what can a distance-time graph be used to show?
it can be used to show motion
if one has a graph with multiple lines on a distance time graph, what do you know about the line of the fastest moving object
it has the largest slope which means it is the steepest
what is acceleration
acceleration is a measure of how quickly velocity changes AND it includes direction
when is an object accelerating
when the object speeds up, slows down or turns
When an object speeds up or slows down how can you calculate its acceleration
a = (Speed final minus speed initial) divided by time
what is momentum a measure of
it is a measure of how hard it is to stop the object
What is momentum's formula
Momentum equals mass times velocity
What happens in a collision
momentum is transferred from one object to another
what is the law of conservation?
the total amount of momentum of a group of objects does not change UNLESS outside forces act on the objects