Motion Flashcards
How to calculate distance travelled
Distance travelled = speed (m/s) / time (s)
How to calcualte average speed
Average speed (m/s) = total distance (m) / total time (s)
What is a vector
A value that has both direction and magnitude
Examples:
- displacement
- velocity
- acceleration
- force
- weight
- momentum
What is a scalar
A quantity that has magnitude but no direction
Examples
- speed
- distance
- temperature
- mass
- time
What is the difference between distance and displacement
Distance is scalar, meaning it has a magnitude but no direction, but displacement is vector, which means it has both magnitude and direction
What is the difference between speed and velocity
Speed is a scalar quantity, meaning that it has no direction but velocity is a vector quantity meaning it has both magnitude and direction
You are cycling behind a lorry at 15mph, The lorry is going at 30mph. Find the velocity of the lorry driver relative to you
30-15 =15
= 15mph
What is acceleration
The change in velocity per second
How to calculate acceleration
Acceleration (m/s^2) = change in velocity (m/s) / time (s)
How top calculate acceleration if you know final and initial velocity
Acceleration (m/s^2) = final velocity - initial velocity / time
How to calculate speed from a graph
Find the gradient of the line
Speed = change in distance / change in time
How are displacement time and distance time graphs different
A distance time graph shows the total distance travelled, a displace smth time graph shows the goals displacement
On a distance time graph, the line is able to keep going up, Beucase the y axis shows distance, and as the distance goes up. So does the line.
On a displacement time graph, the line can go up or come back down the the place it started , as the y axis shows the displacement, and x shows tume
How to find graph with larger displacement
To find the graph with the larger displacement,you find the area under it.
If it a graph which goes up and down with negatives ad a graph with a triangle and rectangle (eg question 3 in year 9 EOY)
If you measure distance travelled and time,
You can play a distance time graph
And the gradient will be equal to speed
So then you can plat a speed time graph
And the gradient is equal to acceleration
If you measure distance from a starting point and time
You can plot a distance time graph
And the gradient is equal to velocity (speed + direction)
So then You can plot a velocity time graph
And the gradient is equal to acceleration (magnitude) + direction
