Motion in One Dimension Flashcards
What is a vector?
A physical quantity which has both magnitude and direction
What is a scalar?
A physical quantity which has magnitude only
What is distance?
The length of a path
What is a displacement?
A change in the position of something
What is magnitude?
The size of a physical quantity
What kind of quality is speed?
A scalar
What kind of quality is distance?
Scalar
What kind of quality is energy?
A scalar
What kind of quality is velocity?
A vector
What kind of quality is mass?
Scalar
What kind of quality is weight?
Vector
How is a vector represented?
A straight line-the length of the line represents the magnitude
An arrow head- shows the direction
How is direction described?
Conventional points (Left, right, etc.) Cardinal points (North, South etc.) In degrees (measured from the horizontal)
What is a resultant vector?
A single vector that has the same effect as all the component vectors together would have
How do you get resultant vectors?
Formula first
Replace with numbers
Write the answer with the magnitude and the direction
What is a maximum vector?
It is when two vectors act in the same direction, i.e the angle between them is 0°
How do you get the resultant vector of a maximum resultant?
Find the sum of the two magnitudes
What is a minimum resultant?
It occurs when two vectors act in opposite directions i.e the angle between them is 180°
How do you get the resultant vector of a minimum resultant?
Find the difference between the magnitudes of the two vectors
When adding two vectors with opposite directions, how do you show direction?
The vector going to the right is positive
The vector going to the left will be negative
If your final answer is positive the resultant vector is to the right
If your final answer is negative, the resultant vector is to the right
Explain the difference between displacement and distance
Someone walks forward 3m
They then walk backward 3m
Their displacement is 0 (they are in the same place)
Their distance is 6m (that is how far they travelled)
How is position measured?
Relative to a reference point
What kind of quantity is position?
A vector
What is the symbol for position?
X
What is a reference point?
A starting point for a vector
How is displacement represented?
By Δx
How do you work out displacement?
By figuring out what the straight line distance between the reference point and the new position is
The direction in which the body has moved
What kind of quantity is displacement?
A vector quality
How can you change the resultant of two vectors without changing the magnitude?
Change the angle between the two vectors
What is velocity?
Rate of change in displacement divided by time
What is speed?
Rate of change in distance over time
What is velocity measured in?
Metres per second
And the direction
What is speed measured in?
Metres per second
No direction
What is distance measured in?
m
What is displacement measured in?
Metres from a reference point
What happens during acceleration?
The speed increases
What does a constant velocity mean?
For every unit of time, the distance remains the same
What is acceleration?
The rate of change of velocity
What is acceleration measured in?
Metres per second squared
What is the formula for displacement?
Xf-xi= Δx
Final position minus the initial position
How do you find average velocity?
Find your total displacement
Divide by your total time
What is instantaneous velocity?
The velocity at a particular moment
How is instantaneous velocity calculated?
Displacement over an extremely small (almost zero) time interval
What is the base unit of speed and velocity?
m/s
How do you convert km/h to m/s?
Divide by 3,6
What happens to acceleration when velocity increases?
Acceleration is positive
What happens to acceleration when velocity decreases?
It is negative
What two factors could cause negative acceleration?
The object is slowing down
The object is speeding up, but in the opposite direction
What is the difference between speed and velocity?
Velocity acts in a particular direction, speed does not have direction
