# P8 | Forces in balance Key facts Test | (Triple GCSE) AQA

P8 - Trple physics AQA spec (forces) [Does not Include higher topics (Paralellogram of forces & Resolution of forces)] These were key facts I personally wanted to revise. Hope it helps :)

Resources I used to make these cards are from the Oxford AQA revision guide and @Freesciencelessons on youtube:

?
What are scalar and Vector quantities?
Scalar quantities are forces .Vector quantities are forces with Direction
1 of 26
Give an example of a scalar and vector quantity
Scalar= Speed, distance, time, mass energy, power & Vector =Velocity, displacemtn, force, weight, momentum, gravity
2 of 26
What are contact forces?
Two objects that are physically touching to generate a force
3 of 26
What is a non contact force?
Two objects that are physically separated and generating a force
4 of 26
Equation for calculating weight?
Weight (N) = mass (kg) x gravitational field strength (N/kg)
5 of 26
The weight of an object is directly/inversley poportional to the mass of an object?
Weight of an object is DIRECTLY porportional (∝) to the mass of an object
6 of 26
What are elastic materials?
Materials that return to their original shape after being bent or squashed
7 of 26
How many forces do we need to change an object's length or shape?
More than one force is needed to change a shape. Otherwise the object will just be moving
8 of 26
What is inelastic deformation?
When objects do not return to their original shape when stretched or squashed
9 of 26
What is the equation to calculate force needed to stretch an elastic object?
Force(N) = spring constant (N/m) x extension(m) [This is NOT the equation for elastic potential energy]
10 of 26
What is Newton's 1st law of motion?
If forces acting on an object are balanced, the resultant force will be constant.
11 of 26
What is Newton's 2nd law of motion?
The ACCELERATION of an object, is PORPORTIONAL, to the RESULTANT FORCE of an object, and INVERSLEY porportional to the MASS of the object
12 of 26
What is Newton's 3rd law of motion?
When 2 objects interact with each other, the action and reaction forces are the same.
13 of 26
What is the equation to calculate moment?
Moment (N/m) = Force (N) x Perpendicular distance from pivot (m)
14 of 26
How can moment be increased?
By increasing magnitude of force or increasing perpendicular distance from pivot
15 of 26
What are levers used for?
Used as a force multiplier to increase the resultant force by applying a smaller initial force
16 of 26
What are gears used for?
To multiply turning effect of a force.
17 of 26
How does a low gear work?
Low gears have low speed, and high turning affect
18 of 26
How does a high gear work?
High gears have high speed, and low turning effect
19 of 26
What is an Effort? And what is a load?
The force applied to a lever is an effort. The load is the object
20 of 26
What direction does touching gears go in?
Touching gears rotate in opposite directions
21 of 26
What is the centre of mass?
Where mass is concentrated at one point of an object
22 of 26
What hapens at equilibrium to a movement?
Total clockwise movement is equal to total anticlockwise movement
23 of 26
What happens when a freely suspended object loose its turning force?
The freely suspended object will return to equilibrium when turning force is taken away
24 of 26
Where does the centre of mass lie along a symmetrical & flat object?
Centre of mass lies along the axis of symmetry
25 of 26
How can you find the centre of mass for an irregular 2d flat shape?
Freely suspend each corner of the shape and draw lines which align with vertical measurement. Where these points meet is centre of mass
26 of 26

## Other cards in this set

### Card 2

#### Front

Give an example of a scalar and vector quantity

#### Back

Scalar= Speed, distance, time, mass energy, power & Vector =Velocity, displacemtn, force, weight, momentum, gravity

### Card 3

#### Front

What are contact forces?

### Card 4

#### Front

What is a non contact force?

### Card 5

#### Front

Equation for calculating weight?