Forces Flashcards
What is a quantity
Value we can measure
E.g mass, temperature, force
2 types of quantities
Scalar
Vector
Scalar and vector are types of…
Quantity
Which type of quantity has a direction
Vector
Which out of scalar and vector quantity has magnitude only, not direction
Scalar
Magnitude meaning (in terms of quantities)
Size
5 types of scalar quantities
Temperature
Mass
Speed
Energy
Distance
5 types of vector quantities
Velocity
Force
Weight
Displacement
Acceleration
Distance is a type of what quantity
Scalar (magnitude only)
Velocity is a type of what quantity
Vector (has magnitude and direction)
What type of quantity can be represented using arrows
Vector
(As it has a direction)
When using arrows to represent vector quantities what does the length represent
Magnitude
(Direction of arrow shows direction of vector)
How do we draw arrows to show vector quantities
Direction of arrow= direction of vector
Length of arrow represents magnitude- longer arrow= greater magnitude etc
Resultant force meaning
Overall force
When 2 forces act on an object it’s the overall force
What is a force
A push or pull that acts on an object due to interaction with another object
A force is a p.. or p… due to interaction with another object
Push or pull
A force is a push or pull due to interaction with another what
Object
2 types of forces
Contact
Non contact
Contact force meaning
Objects interacting must be physically touching
Non contact force meaning
Objects interacting don’t have to be physically touching
What type of force is air resistance
Contact
(Object physically touched air particles)
Mass is a measure of…
How much matter an object has
What is a measure of how much matter an object has (measured in kilograms)
Mass
True or false, weight is the force on an object due to gravity
True
What is weight
Force on object due to gravity, measured in Newtons
Weight is the force on an object due to…
Gravity
Weight = mass x what
Gravitational field strength
Weight and mass are directly proportional (if one doubles, so does the other)
Relationship between mass and weight
Directly proportional
(Increase at same rate so if one doubles so does the other as weight= mass x gravitational field strength)
When the forces on an object are balanced, what is the resultant force equal to
0
(No overall force)
Why is the resultant force 0 if the forces on an object are balanced
There is no overall force
True or false, when the forces on an object are unbalanced it will accelerate or decelerate
True
2 things that can happen to an object if the forces are balanced
Remains stationary
If already moving stays at constant speed
Name of force acting in opposite direction to movement
Friction
How many forces are needed to bend, stretch or squash an object
2
True or false, 2 forces are needed to bend, stretch or squash an object
True
What is elastic deformation
An object returns to its original shape once forces are removed
(E.g a spring)
What is in elastic deformation/ plastic deformation
Object doesn’t return to original shape when forces are removed
E.g playdough
Elastic vs inelastic deformation
Elastic deformation- object returns to original shape when forces are removed e.g spring
Inelastic deformation- object doesn’t return to original shape when forces are removed e.g playdough
What is meant by spring constant
Amount of force needed to stretch/ squash material by 1m
The extension of a spring is directly proportional to what (Hooke’s law)
Force applied
What does Hook’s law state
Extension of spring is directly proportional to force applied (up to the limit of proportionality)
Another word for the turning effect of a force
Moment of a force
True or false, a force causes an object to rotate
True
A moment is the…
Turning effect of a force
True or false, if the force increases so does the moment
True
As moment = turning effect of the force
Why are door handles always furthest away from the hinge (moment= force x distance from pívot)
So that less force needs to be applied due to equation above
Which type of gears rotate quickly
Small gears
Which type of gears rotate slowly
Big gears
Which type of gears rotate with a big moment
Big gears
Which type of gears rotate with a small moment
Small gears
Small vs big gears
Small gears rotate quickly with small moment
Big gears rotate slowly with big moment
What 2 things can be used to increase the moment of a force to make it easier to lift/ rotate an object
Levers/ gears
What is force measured in
Newtons (N)
What is the magnitude of a force measured in
Newtons
Why are forces vector quantities
Thy have both a direction and magnitude (e.g 5N)
Is tension a contact or non- contact force
Contact
Tension, friction and air resistance are all examples of what type of force
Contact
3 types of non contact force
Gravitational, magnetic, electrostatic
Gravitational, electrostatic and magnetic are examples of which type of force
Non- contact
True or false, the strength of a non- contact force decreases as the objects get further apart
True
If a car travelled at 50 miles per hour, what’s the magnitude of its speed
50
True or false, vectors can be both positive and negative
True
E.g 2km west is - 2km east
What type of diagram can we use to find the resultant force of an object
Free body diagrams
Free body diagram meaning
Simple diagram showing all the forces acting on an object (using force arrows)
If the object has no resultant force acting on it then it’s in…
Equilibrium
When can an object be in equilibrium
If there’s no overall force (resultant force) acting on it
(The forces cancel each other out)
What 2 types of diagram can we use to find the resultant force of an object
Free body diagram
Vector diagram
(A to scale drawing using a ruler to then find the 3rd length of the triangle (resultant force) or using Pythagoras)
In vector diagrams how do we find the direction of the resultant force
Use protractor measuring to the right of the vertical line
Resolving a vector meaning
Splitting it up into its horizontal and vertical components (using scale diagrams)
True or false, a liquid is a fluid
True (as it can flow)
What 2 states of matter are fluids (can flow)
Liquid and gas
Pressure is caused when…
Objects exert force on each other
What is caused when objects exert force on each other
Pressure
What 2 things does pressure depend on
Magnitude (size) of force
Size of area in contact
(As pressure= force/ area)
What is pressure measured in
N/m squared or Pascals
Another word for forward force
Thrust force
In a fluid does the pressure increase or decrease with depth
Increase
What is the average walking speed in m/s
1.5 m/s
What is the average running speed in m/s
3m/s
What is the average cycling speed in m/s
6m/s
In a distance- time graph what does the gradient represent/ tell you
Speed
(Steeper gradient is faster)
In a distance time graph what does a horizontal line represent
Not moving (stationary) as the speed is 0
Acceleration = change in velocity over what
Time taken
Acceleration describes the what
Change in velocity per second
(Therefore equation is change in velocity/ time taken)
Unit for acceleration
m/ second squared
Which out of liquid and gas is compressible
Gas
(Liquids are incompressible)
Compressible meaning
It’s volume can change when pressure is applied to it e.g in gases
In a velocity time graph what does a horizontal line represent
Moving at a constant speed
In a velocity time graph what does the positive gradient represent
Acceleration
How to work out distance travelled in velocity time graph
Area under graph (curve)
Terminal velocity is reached when all forces are what
Balanced
What 2 factors is the stopping distance of a car made up of
Thinking distance
Breaking distance
Instrument used to measure weight of object
Newton-meter
(Calibrated spring balance)
Will an object sink if it’s weight is greater than or less than the upthrust
Greater than
An object will float if its weight is equal to what
The upthrust
Displacement meaning
Distance and direction of a straight line from the object’s starting point to finish point
Pressure in a liquid depends on the what of the liquid
Depth
The pressure in a fluid causes a force to act at how many degrees to a surface
90 degrees
Name for thin layer of air around the Earth
Atmosphere
Does the atmosphere get more or less dense with increasing altitude
Less
Why does the atmosphere get less dense with increasing altitude
Higher altitude means fewer particles due to less weight of particles above pushing them together
(And density is a measure of number of particles per cubic metre)
