Chap 1 - Concepts of Motion Flashcards
The location of an object in relation to some “reference point”
Position
The symbol for time
t
In linear motion, the “+” and the “-“ symbols are used to show what?
Direction
Acceleration
That rate at which you change your velocity.
Example:
Every second, he was going 5mph faster than the second before.
A quantity that has both magnitude and direction.
Example:
Forces are vectors because if you push or pull on something, there is a magnitude (size) of your push, and there is always a direction of your push.
Vector
Velocity at clock reading = t
<span>v</span>t
A point or exact location that can be used to help describe the location of some other point or object.
Reference Point
Constant Speed
Not speeding up or slowing down
A letter written smaller and below the rest of the writing.
<span>v</span>t
Here the “ t “ is subscripted
Subscript
Another way of saying that someone is accelerating in such a fashion that each second they were going 7 meters per second faster than the second before?
Acceleration = (7 m/s) / s
or
7m/s2
In motion along a line, what is the difference between the following two “velocities?”
17 m/s
-17 m/s
The objects are traveling at the same speed, but in opposite directions.
In linear motion, we can use plus and minus to represent different directions.
Reference Point
A point or exact location that can be used to help describe the location of some other point or object.
This is called a
Motion Diagram
(aka Motion Map)
Scaler
A quantity that has a magnitude (size) but no direction.
Examples:
Temperature. 78 degrees tells you how “big” the temperature is, but there is no direction to 78 degrees.
In order to describe the position of an object, you must always refer to a ___________ _____________.
Reference Point
(or reference object)
Speed
How fast an object is traveling.
(Direction is not important)
Average Speed
A single speed that can be used to represent an object’s speed during a period of time, even if the object is changing speeds.
Is velocity a vector or a scaler?
Velocity is a vector.
It has both magnitude (size) AND direction.
Example:
Her velocity was 30 mph north.
Which object is moving faster?
A car going +10 mph
A moped going - 10 mph
Neither.
They are both going the same speed, but in different directions.
<span>x</span>0
Position at clock reading = zero
x
the symbol for position
(X marks the spot)
Velocity/Time graph
A motion graph with time on the horizontal axis and velocity on the vertical axis.
a
The symbol for acceleration
Vector
A quantity that has both magnitude and direction.
Example:
Forces are vectors because if you push or pull on something, there is a magnitude (size) of your push, and there is always a direction of your push.
Position at clock reading = “t”
<span>x</span>t
<span>v</span>t
Velocity at clock reading = t
the symbol for distance
d
Displacement
How far you are from where you started, and in what direction.
How big something is.
Magnitude
That rate at which you change your velocity.
Example:
Every second, he was going 5mph faster than the second before.
Acceleration
The symbol for acceleration
a
Velocity
The speed and direction an object is travelling.
How fast an object is going at an instant in time. It is what is shown on the speedometer of a car.
Instantaneous Speed
<span>v</span>0
Velocity at clock reading = zero
Velocity at clock reading = zero
<span>v</span>0
Which object is moving the fastest?
A
The steepest line on a position/time graph represent the fastest moving object.
(A is moving the opposite direction from B and D)
In linear motion, how will we show the direction an object is travelling?
With a “+” sign or a “-“ sign.
The plus would mean one direction, and the minus would mean in the exact opposite direction.
Is “speed” a scaler or a vector?
It is a scaler. Speed has a magnitude (size) but no direction.
Example: 50 mph.
Which object is not moving?
C
Look carefully at the following graph. Does this show and object that is moving or standing still.
Linear Motion
Motion along a line
A quantity that has a magnitude (size) but no direction.
Examples:
Temperature. 78 degrees tells you how “big” the temperature is, but there is no direction to 78 degrees.
Scaler
Magnitude
How big something is.
Subscript
A letter written smaller and below the rest of the writing.
<span>v</span>t
Here the “ t “ is subscripted
d
the symbol for distance
If you say a ball is 30 feet up, what would typically be your reference point.
The ground below the ball.
(The ball would be 30 feet away from the reference point or ground in this case)
the symbol for velocity
v
acceleration / time graph
A motion graph with time on the horizontal axis and acceleration on the vertical axis.
In linear motion, the difference between
-55 mph
and
+55 mph
is?
Direction only
When you describe the velocity of a car, your typical reference object would be what?
The surface of the road beneath the car.
v
the symbol for velocity
The study of motion
Kinematics
When they describe the “top velocity” of a type of airplane, the reference object they would typically use would be what?
The air the plane is flying in.
acceleration / time graph
A motion graph with time on the horizontal axis and acceleration on the vertical axis.
Motion
A change in an objects postion over some time interval.
translational motion
motion where an object travels from one place to another.
Trajectory
The path along which an object moves.
Particle
An object that can be represented as a mass at a single point in space.
Particle Model of Motion
A simplification in which we treat a moving object as if all of its mass were concentrated at a single point.
Position Vector
An arrow drawn from the “origin” to an object’s position.
Linear
Along a line
SI Units
The International System of Units.
What are the basic SI units
seconds
meters
kilograms
“Order of Magnitude” Estimate
A one significant figure estimation or calculation.
The study of motion
Kinematics
If you are in a car and you feel any of the things below, you know you are ______________.
- Pushed back into your seat.
- Thrown forward into your seatbelt
- Pushed sideways into the door.
accelerating
