forensics 2025

Friction

Friction is a type of force that resists the motion of an object.

Air Resistance

Type of resistance when an object moves through air.

Water Resistance

Type of resistance when an object moves through water.

Magnetism

When the object is attracted to something made out of iron, cobalt, or nickel.

Elastic

Force that causes a squashed or stretched object to return to its original shape.

Tension

A force that pulls inward when a solid object, such as a rope, is stretched.

Gravity

An attractive force between objects that have a mass.

Applied Force

Force exerted by a person, machine or animal.

Contact Force

Any force that can only occur when two objects are touching.

Non-Contact Force

Any force that can occur even when two objects are not touching.

Balanced Force

When forces act on an object in opposite directions and are the same size they are known as balanced forces.

Unbalanced Force

A force that doesn't have an equal and opposite force acting on the same object.

Inertia

The tendency of an object to resist changes in its state of motion.

Free Body Diagram

A graphical representation used to visualize the forces acting on an object.

Net Force

The overall force acting on an object after all the forces are combined.

Newton's First Law of Motion

An object at rest stays at rest and an object in motion stays in motion unless acted upon by a net external force.

Newton's Second Law of Motion

The acceleration of an object is directly proportional to the net force acting on it and inversely proportional to its mass.

Newton's Third Law of Motion

For every action, there is an equal and opposite reaction.

Characteristics of Reaction Forces

Reaction forces are equal in size and opposite in direction to the action forces.

Relationship Between Force and Acceleration

Force is equal to mass times acceleration (F = ma).

Friction

Friction is a type of force that resists the motion of an object.

Air Resistance

Type of resistance when an object moves through air.

Water Resistance

Type of resistance when an object moves through water.

Magnetism

When the object is attracted to something made out of iron, cobalt, or nickel.

Elastic

Force that causes a squashed or stretched object to return to its original shape.

Tension

A force that pulls inward when a solid object, such as a rope, is stretched.

Gravity

An attractive force between objects that have a mass.

Applied Force

Force exerted by a person, machine or animal.

Contact Force

Any force that can only occur when two objects are touching.

Non-Contact Force

Any force that can occur even when two objects are not touching.

Balanced Force

When forces act on an object in opposite directions and are the same size they are known as balanced forces.

Unbalanced Force

A force that doesn't have an equal and opposite force acting on the same object.

Inertia

The tendency of an object to resist changes in its state of motion.

Free Body Diagram

A graphical representation used to visualize the forces acting on an object.

Net Force

The overall force acting on an object after all the forces are combined.

Newton's First Law of Motion

An object at rest stays at rest and an object in motion stays in motion unless acted upon by a net external force.

Newton's Second Law of Motion

The acceleration of an object is directly proportional to the net force acting on it and inversely proportional to its mass.

More force, more acceleration: If you push a cart with double the force, it will accelerate twice as much.

• More mass, less acceleration: If you push an empty cart and a cart full of bricks with the same force, the empty cart will accelerate much faster because it has less mass.

• Acceleration is a change in velocity: Acceleration is the rate at which an object's speed and/or direction changes.

• F=macap F equals m a

  𝐹=𝑚𝑎

  : This equation shows that force is the product of mass and acceleration.

• Net force: The 'F' in the equation refers to the total, or net, force on the object. This is the sum of all forces acting on it. 

Newton's Third Law of Motion

For every action, there is an equal and opposite reaction.

Characteristics of Reaction Forces

Reaction forces are equal in size and opposite in direction to the action forces.

Relationship Between Force and Acceleration

Force is equal to mass times acceleration (F = ma).

distance

how far the object has travelled

displacement

how far the object is from its origin

scalar

doesnt have a direction eg. distance

vector

does have a direction eg. displacement 

kinematics

the description of motion

speed

measure of how fast the object is moving

instantaneous speed

the speed of an object at a specific moment in time

average speed

total distance/the total time taken

velocity

a vector quantity that measures the rate of change of an object’s displacement and specifies both its speed and direction of motion

ethical concerns of driverless cars

1. terrorism use

2. criminals could use it to get away

3. legal problems, who’s to blame in an accident?

4. loss of jobs 

difference between instantaneous and average speed

average speed represents the overall speed of an object over a period, instantaneous speed is the objects speed at a specifc moment in time

difference between speed and velocity

speed is scalar that measure how fast a object is moving, whilst velocity is a vector quantity that measures the speed and direction of an object’s motion

acceleration

any change in velocity

what units are used to measure acceleration?

there are 3 ways: increase/decrease in speed and a change of direction. standard unit is m/s/s