Scalars, Vectors and Reference Frames Flashcards
We've talked about how Physics uses measurements. We can categorize the measurements as scalar or vector quantities.
What is a scalar?
Measurements with magnitude, but no direction, such as time, volume, and weight.
What is a vector?
Measurements that have both magnitude and direction, such as velocity and displacement.
How are scalar quantities represented?
One dimensional, represented by a number and unit.
What rules do scalar quantities follow?
Basic rules of algebra, allowing addition, subtraction, multiplication, and division.
How are vectors represented?
Multi-dimensional, including a number, unit, and direction, typically represented as arrows.
What is a frame of reference in physics?
A coordinate system used to define measurements like position and velocity.
Why do we prefer stationary reference frames?
Because the math is simpler and the answers will be consistent for everyone.
Does the frame of reference affect vector length?
No, the length of a vector remains the same in any stationary reference frame; only the direction may change.
What is a commonly used reference frame in physics?
A Cartesian coordinate system with the origin at the starting point of motion.
How can a vector be represented using unit vector notation?
By convention, ‘i’ indicates the x-component, ‘j’ the y-component, and ‘k’ the z-component.
What defines a vector?
A quantity that has both magnitude and direction.
How can one-dimensional vectors be described?
By an x-coordinate that moves along the x-axis.
What coordinates do two-dimensional vectors have?
X and y coordinates, shown in an x-y plane.
What coordinates do three-dimensional vectors include?
X, y, and z coordinates.
What is speed?
A scalar that measures how fast an object is moving without direction.
What is velocity?
Speed with an associated direction, making it a vector.
What is acceleration?
A vector that measures the rate of change of velocity.
What is displacement?
A vector that indicates how far away something is from the starting point, considering direction.
What is distance?
A scalar that measures the total distance traveled between two places.
What is time in physics?
A scalar that measures the length of duration between two events.
What is vector addition?
A fundamental operation used to find the sum of two or more vectors, combining their magnitudes and directions.
What is the ‘tip to tail rule’ in vector addition?
Vectors are arranged such that the head of one vector touches the tail of the next.
How is a resultant vector drawn?
From the tail of the first vector to the head of the last vector.
What shape is formed when finding the displacement or position vector?
A right triangle.
How do you determine the angle of a vector in a Cartesian coordinate system?
Adjust the angle based on which quadrant the vector is in, measured from the positive x-axis.
How do you subtract vectors?
By ‘adding the opposite’, reversing the direction of the vector while keeping its magnitude.
