Topic 1 - Motion and Forces Flashcards
What is a scalar quantity?
A physical quantities that had magnitude (size), but no direction
What is a vector quantity?
A physical quantity that has both magnitude (size) and direction
What are some examples of a scalar quantity?
- Distance
- Mass
- Speed
- Time
- Energy
- Power
What are some examples of a vector quantity?
- Weight
- Displacement
- Velocity
- Force
- Current
- Acceleration
- Momentum
- Pressure
What happens to the velocity of an object moving around in a circle at constant speed?
Its velocity is continuously changing, as the direction is always changing, e.g., a car going around a roundabout
What is the speed of a person walking?
1.5m/s
What is the speed of a person running?
3m/s
What is the speed of a person cycling?
6m/s
What is the speed of wind speed?
5-20m/s
What is the speed of a car in a built up area?
13m/s
What is the speed of a car on the motorway?
30m/s
What is the speed of a train?
55m/s
What is the speed of a plane?
250m/s
What is the speed of a ferry?
15m/s
What is the speed of sound in air?
340m/s
How do you calculate speed?
speed = distance ÷ time
How do you calculate the distance travelled?
distance = speed * time
What is the symbol equation to calculate the distance travelled?
x = v * t
What is distance measured in?
m (metres)
What is time measured in?
s (seconds)
What is speed measured in?
m/s (metres per second)
What is acceleration?
How quickly velocity is changing, e.g., speed or direction
How do you calculate the acceleration?
acceleration = change in velocity ÷ time
What is the symbol equation to calculate acceleration?
a = (v - u) ÷ t
What is acceleration measured in?
m/s^2
How do you calculate the change in velocity?
final velocity (v) - initial velocity (u)
What is the acceleration for objects in free fall?
10m/s^2
How do you calculate uniform acceleration (constant acceleration)?
v^2 - u^2 = 2 * a * x
What is free fall?
When you assume that gravity only acts on the object, and no extra force is being applied on the object
What are the forces acting on a plane?
- Drag (backwards)
- Lift (upwards)
- Thrust (forwards)
- Weight (downwards)
What are the forces acting on a submarine?
- Water resistance (backwards)
- Buoyancy force (upwards)
- Engine force (forwards)
- Weight (downwards)
What is a distance/time graph used for?
A way of describing the motion of something moving in a straight line