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.
