Paper2: Forces - scalar/vector quantities, types of forces Flashcards
State examples of scalar quantities
Mass
Temperature
Speed
Energy
Distance
Time
Volume
Define scalar quantity
A Scalar quantity is a physical quantity that has magnitude (size or amount) only, without any specific direction
Explain why distance gives us no idea of the direction
Distance gives us no idea of the direction. This is because distance is a scalar quantity
State examples of vector quantities
Displacement
Weight
Force
Velocity
Acceleration
Momentum
Electric field
Define vector quantity
A vector quantity is a physical quantity that has both magnitude and direction
Define displacement
Displacement is distance in a given direction
Explain why displacement is a vector quantity
This is because displacement is distance in a given direction
Give an example of a displacement measurement
500 m due West
Give an example of a displacement measurement
500 m due West
How can vector quantities be represented
Vector quantities can be represented using an arrow
Define force
A force is a push or a pull that acts on an object due to the interaction
with another object.
https://filestore.aqa.org.uk/sample-papers-and-mark-schemes/2021/november/AQA-84632H-QP-NOV21.PDF
question 7.1
What name is given to force A?
friction
What does the length of the arrow and the direction represent for a vector quantitiy
The length of
the arrow represents the magnitude, and the direction of the arrow represents the direction of the vector quantity.
The average speed of a car between the cameras and the average velocity of the car
between the cameras are different
velocity is a vector and speed is
a scalar
road is not straight
therefore direction changes so
the velocity changes
What do all forces have
All forces have both magnitude (size) and direction
Forces - vector quantity
State the two types of forces
Contact forces
Non-contact forces
What is the unit of force
Newton (N)
When do all forces occur/take place
All forces take place when two objects interact
Define contact force
A contact force is a force that acts on objects only when the objects physically touch each other
Define non-contact force
A non-contact force is a force that acts on objects that are physically separated
Examples of contact forces
Tension (e.g. in a rope)
Friction
Air resistance
Normal contact force
Examples of non-contact forces
Gravitational force (attracts all objects to other objects e.g. this force attracts the international space station to the earth and the earth to the space station)
Electrostatic force (the force between two charged objects - electrostatic forces of attraction and repulsion)
Magnetic force (the force experienced by certain objects in a magnetic field)
Describe how tension in a rope is created
The force of tension is pulling on the soldier
Explain the role of friction in an aeroplane landing on the water
The force of friction is acting between the water and the aeroplane.
This causes the aeroplane to slow down and come to a stop
Define friction
Friction is a resistive force that slows things down and tries to stop objects sliding past each other
In which direction does friction act
Friction always acts in the opposite direction to which an object is trying to move
Define air resistance
Air resistance is friction caused by movement through air
Define upthrust
Upthrust is the upward force acting on an object. which is caused by the water around that object
Explain the role of air resistance acting on the skydiver
As the skydiver falls through the air, air particles collide with the parachute. This causes the force of air resistance to act upwards
Define drag
The friction caused by an object moving through a liquid (E.G. water) is known as drag
Label the forces acting on the moving fish
_____upthrust
*
|
thrust<— fish ->friction
|
*
__________weight
Label the forces acting on a boat
upthrust acting upwards
air resistance acting in the opposite direction to thrust
Weight acting downwards
Friction acting between the water and the boat
Explain the role of the normal contact force
E.g. a lamp on a table
The lamp is exerting a downward force on the table. This force is weight
At the same time, the table is exerting an upward force on the lamp
This force is called the normal contact force
When can the normal contact force only occur
The normal contact force can only happen if the two objects are in direct contact
Swimmers practise diving to the bottom of the swimming pool to pick up the
diving brick.
Explain why the forces on the brick at the bottom of the pool cause the brick to be
stationary.
upthrust acts (upwards on the
brick)
normal contact force acts
upwards (on the brick)
weight is equal to upthrust plus
normal contact force
