P4 Flashcards
What is the formula for speed?
Distance traveled (m) / time taken (s)
What is speed measured in?
m/s
What is it called if you measure average speed over a very short time period?
Instantaneous speed.
What is the displacement of an object?
The distance from its start point to the straight line?
How is displacement expressed?
As a distance with a direction.
Are displacement and velocity scalar or vector quantities?
Both vector.
What is the velocity of an object?
It’s speed in a certain direction.
What is the formula for average velocity?
displacement/time taken.
What is a distance-time graph used for?
To visualize a journey.
In a distance-time graph, what is plotted against the y-axis and what is plotted against the x-axis?
Y-axis : the time
X -axis: the distance travelled
In a distance-time graph, what does a horizontal line mean?
The vehicle is stationary.
In a distant-time graph, what is the gradient of the line equal to?
The speed.
In a distant-time graph, the steeper the gradient…
the faster the speed.
In a distant-time graph, what does a curved line mean?
The speed is changing.
In a distant-time graph, what does it mean if a curve is getting steeper?
the vehicles speed is increasing.
What is a displacement time-graph used for?
To visualize return journeys.
What is acceleration?
The rate at which the speed of an object increases.
What is acceleration measured in?
m/s^2
Acceleration=
change in speed (m/s) / time taken (s)
What is deceleration?
When an object slows down.
What has to be acting on an object to cause acceleration (or deceleration)?
A force.
When the net or overall force is zero, the acceleration is…
zero.
What is a speed-time graph used for?
to show the changes in speed during a journey.
In a speed-time graph, what is plotted on the x-axis and what is plotted on the y-axis?
Y axis: speed
X axis: time