B: Physics = Changes in Motion 1.3 Average Velocity Flashcards
What is position in relation to a reference point?
Position is the distance and direction of a location relative to a reference point
Example: If Melissa and Usha are at the John Creek crossing, their position is 5.0 km north of base camp.
How is position quantified?
Position is a vector quantity
A vector quantity describes the location of a point relative to a reference point.
What is a vector?
A vector is a quantity consisting of magnitude and direction
Vectors are used to represent position because they include both distance and direction.
Why is position considered a vector?
Because each position measurement includes a direction
The direction is crucial for defining the position relative to a reference point.
What symbol is used to denote position to indicate direction?
The symbol for position includes an arrow over the variable
This notation signifies that the quantity includes direction.
Fill in the blank: Position is defined as a ______ quantity describing the location of a point relative to a reference point.
vector
True or False: Distance and position are the same concepts.
False
Position includes both distance and direction, while distance is a scalar quantity.
What is the sign convention?
An agreement about which direction is positive and which is negative
Sign conventions are often used in physics to simplify problems involving direction.
Fill in the blank: In situations like this, it is often convenient to use a _______.
sign convention
What is the symbol for displacement?
Δd with an arrow on top pointing to the right
The Greek letter delta (Δ) represents ‘change in.’
Define displacement.
A vector quantity describing the length and direction in a straight line from the starting position to the final position.
What does average velocity describe?
A vector quantity describing the change in position over a specified time.
How is average speed different from average velocity?
Average speed does not reveal anything about the direction of motion.
Fill in the blank: The term that describes both the magnitude of how fast an object is moving and the direction it is moving is called _______.
average velocity
True or False: Speed and velocity are used interchangeably in everyday speech.
True
What does the term ‘scalar’ refer to in the context of speed and velocity?
A quantity that has only magnitude and no direction.
What is the difference between displacement and distance?
Displacement is a vector quantity, while distance is a scalar quantity.
What is displacement in physics?
Displacement is the change in position between the starting point and the ending point.
What is the resultant displacement?
The resultant displacement is the vector sum of individual displacements.
What is the head-to-tail method?
The head-to-tail method is a method where the tail of a succeeding vector arrow begins at the head of the preceding vector arrow.
How is the resultant displacement represented?
The resultant displacement is represented by a third arrow drawn from the tail of the first vector to the head of the second vector.
What does the length of the arrow in a scale diagram represent?
The length of the arrow represents the magnitude (the number of kilometres).
What does the direction of the arrow in a scale diagram indicate?
The direction of the arrow indicates the direction of motion.
What is a scale diagram used for?
A scale diagram is used to visually represent each of the position vectors with an arrow.
Fill in the blank: The value 1.2 km[N] is called the _______.
resultant displacement.
True or False: The vector approach to finding displacement always yields the same outcome as the scalar solution.
False.
What is the significance of the resultant displacement in a journey?
It summarizes the overall change in position from start to finish.
What do you need to do to find the displacement for the entire journey?
You need to correctly draw one vector to scale and then start the next scale drawing at the head of the first vector.
What is the definition of position in physics?
Position is the distance and direction of a location relative to a reference point.
What is a term used to describe a change in position?
Displacement.
How is average velocity calculated?
Average velocity = displacement / elapsed time.
What is the relationship between displacement and elapsed time?
Average velocity is determined by dividing displacement by elapsed time.
Fill in the blank: The resultant displacement is the sum of the individual _______.
[displacements].
What method can be used to determine resultant vectors such as displacement?
Scale diagram and the head-to-tail method.
True or False: Displacement is a scalar quantity.
False.
What type of quantity is average velocity?
Vector quantity.
