Physics

Front 1

Scalar

Back 1

Scalar quantities measured in numbers and units. e.g. length, temperature and time.

Front 2

Vector

Back 2

Measured with numbers and units but also have a specific direction.

Front 3

Distance

Back 3

How far an object has moved (in metres, m)

Scalar quantity.

Front 4

Displacement

Back 4

Straight line distance between starting and finishing points (metres, m)

Vector Quantity

Front 5

Speed

Back 5

Rate at which an object covers distance (m/s or ms^-1)

Scalar quantity

Speed = distance / time

Front 6

Velocity

Back 6

Rate at which an object's position changes.

A vector quantity.

Average velocity (V = displacement (s) / time (t))

Front 7

Mass

Back 7

Looking at matter

Front 8

Thinking Distance

Back 8

Distance a vehicle travels in the time it takes for a drive to react and apply brakes.
Impacting factors include age and alcohol intake.

Front 9

Braking Distance

Back 9

Distance a vehicle takes to stop once the driver applies brakes.

Impacting factors include weather and speed.

Front 10

Overall

Back 10

Faster a vehicle is travelling, the longer it takes to stop. Overall distance this takes is the stopping distance.

stopping distance = thinking distance + braking distance

Front 11

Acceleration

Back 11

Rate at which an object changes its velocity. Unit is ms^-2.

Formula:

Front 12

Speed-time graphs

Back 12

Acceleration is calculated by dividing speed by time. Gradient = change in speed / change in time which equals acceleration.

*Negative gradient means object is decelerating.

The area under the line is distance travelled.

e.g. Area of (trapezium - under the line). distance = speed X time

Front 13

Distance-time graphs

Back 13

Gradient gives speed.

Steep slope faster speed (bigger number).

Front 14

Displacement-time graphs

Back 14

The gradient of this graph gives velocity.

Front 15

Velocity-time graph

Back 15

Gradient gives acceleration.
Area under line gives change in displacement.

Front 16

Force Diagram

Back 16

The forces acting on any object can be shown using a force diagram.

Front 17

Force Diagram explained

Back 17

A force diagram uses labelled arrows to show all the forces acting on the object.

-The direction of each arrow shoes the direction of the force.

-The length of each arrow is proportional to the size of the force.

Front 18

Upthrust

Back 18

Upthrust is the upwards force (on the fish) caused by (the water around the fish sometimes called buoyancy).

Front 19

Thrust

Back 19

Forwards force created by (fish, car etc).

Front 20

Air Resistance

Back 20

Air resistance is the friction caused by movement through air.

As speed of falling object increases, air resistance increases.

Front 21

Forces in general

Back 21

There are usually several different forces acting on a subject. The overall motion of the object will depend on the size and direction of all the forces.

Front 22

Resultant Force

Back 22

The motion of the object will depend on the Resultant force. The resultant force is calculated by adding all the forces together taking direction into account.

e.g. Crate being moved 50N to the left and 30N to the right. Resultant force = 50-30

= 20N to the left.

Front 23

Force

Back 23

A push or pull on an object. It usually changes an object from a state of rest or changes an objects velocity.

Front 24

Newton's First Law

Back 24

If the forces on a object are balanced the object will continue to do what it is already doing.

If the object is stationary it will remain stationary. If the object is moving it will continue to move at the same speed and in the same direction.

Front 25

Newton's First Law continued...

Back 25

This tendency to resist a change in motion is called an object's Inertia. The larger the mass of an object, the greater its inertia.

Front 26

Newton's Second Law

Back 26

If the resultant force acting on an object is not zero, all the forces are said to be unbalanced.

If the forces on an object are unbalanced two things about the object can change:

1. Speed of an object may change (increase or decrease).

2. The direction of motion may change.

Front 27

Newton's Second Law formula

Back 27

Resultant force acting on an object is related to the object's mass and acceleration.

Force = mass x acceleration (F = ma)

*mass must always be in kg.

Force measured in Newtons.

Acceleration measured in metres per second (ms^-2).

Front 28

Newton's Second Law continued

Back 28

The force F that appears in the second law is the net force.

To solve problems with multiple forces:

-Add up all the forces to get a single net force.

-Before calculatng any resulting acceleration.

Front 29

Newton's Third Law

Back 29

Whenever one object exerts a force on a second object, the second object exerts an equal and opposite force on the first.

We call one force the 'action force' and the other the 'reaction force.'

Therefore: To every action there is always an opposed equal reaction

Front 30

Energy

Back 30

The ability to make things happen.

Front 31

Kinetic Energy

Back 31

The energy an object has because it is moving.

Formula:

KE = 1/2 x mass x velocity^2

Mass (kg), Velocity (m/s), KE (Joules, J)

Front 32

Impacts of Mass and Speed

Back 32

Doubling the mass of a moving object doubles its Kinetic Energy.

Doubling the velocity quadruples its Kinetic Energy.

Therefore increasing vehicle speed has the greatest impact on Kinetic Energy.

Front 33

Gravitational Potential Energy

Back 33

GPE is the amount of energy an object has because of its position above the ground i.e its height.

GPE = mass x gravitational field strength x height

Mass (kg), GFS (Newtons per kg usually 10N/kg), Height (m) GPE (Joules, J)

Front 34

Gravity

Back 34

Force that exists between any 2 objects that have mass.

Falling object accelerates towards Earth because of force of gravity, therefore speeding up when falling.

Front 35

Weight

Back 35

Measure of the force of gravity pulling on an object.

Therefore, something will weigh less where the gravitational force on its mass is weaker (as seen on the moon or in space), even though mass has not changed.

Front 36

Terminal Velocity

Back 36

As speed of falling object increases, air resistance increases. At some speeds: air resistance = gravitational pull (cannot get any faster). At this point, the object ceases to accelerate and continues falling at a constant velocity called terminal velocity.

Front 37

General (objects moving towards Earth)

Back 37

In absence of other forces: air resistance, all falling objects regardless of their mass, accelerate towards Earth at the same rate.