Speed and Motion Flashcards
What is a vector quantity
A value that has both magnitude (size) and direction (e.g. up, down, 214°, East, Right etc…)
Name 4 examples of Vector Quantities
Force, Displacement, Velocity, Acceleration
What is a scalar quantity
A value that has magnitude (size) but no sense of direction
Name 5 examples of scalar quantities
Mass, Temperature, Time, Distance, Speed
What is the difference between Speed and Velocity
Both are a measure of how fast an object is travelling but speed is a scalar quantity and it only describes how fast the object is moving while velocity is a vector quantity so it measures how fast and what direction in which an object is moving
How fast do you go when you walk
1.5m/s
How fast do you go when you run
3.0m/s
How fast do you go when you cycle
6.0m/s
How fast does a car usually go
30-70mph or 13 to 30m/s
What is the Speed of Sound
330 to 340 m/s
If you see a triangle in a formula what does it mean
It means Delta which means ‘change in…’
Features of a Displacement-Time Graph
Diagonal Line - Constant Speed
Horizontal Line - Stationary
Steeper Diagonal Line - Faster Constant Speed
Diagonal Line Downwards - Constant Speed in opposite direction
Gradient increasing (Curve) - Acceleration
Gradient decreasing (Curve) - Deceleration
What is instantaneous speed
The gradient of a distance-time graph at 1 singular point
What is average speed
The total distance divided by the total time
How can you calculate instantaneous speed
Using a tangent (a line that touches only one point on a circle or arc or line) If you can find the gradient of this tangent, you have found the speed of that object at that one singular point in time.
What is acceleration
The rate of change of velocity (measured in m/s²)
