Force and Motion Study Notes

flashcards

Force

A push or pull acting on an object.

Motion

Change in position of an object over time.

Uniform Motion

Motion at constant speed in a straight line.

Non-Uniform Motion

Motion with varying speed or direction.

Inertia

Resistance of an object to change its state.

Mass

Amount of matter in an object, measured in kg.

Momentum

Product of mass and velocity of an object.

Balanced Forces

Equal forces acting in opposite directions, no movement.

Unbalanced Forces

Unequal forces causing a change in motion.

Friction

Force opposing motion between two surfaces in contact.

Rolling Friction

Friction when an object rolls over a surface.

Sliding Friction

Friction when an object slides over a surface.

Thrust

Force exerted by an object in a specific direction.

Pressure

Force applied per unit area, measured in Pascals.

Acceleration

Rate of change of velocity over time.

Newton's First Law

An object remains at rest or in uniform motion unless acted upon.

Newton's Second Law

Force equals mass times acceleration (F=ma).

Newton's Third Law

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

Activity 10.1

Experiment demonstrating force changes shape of objects.

Activity 10.2

Experiment showing effects of balanced and unbalanced forces.

Example of Friction

Braking a bicycle to slow down.

Example of Inertia

A ball remains at rest until kicked.

Example of Momentum

A moving car has momentum based on speed.

Balanced Forces

Equal forces that do not cause motion.

Unbalanced Forces

Unequal forces causing motion change.

Inertia

Tendency to resist changes in motion.

Mass

Measure of an object's inertia.

Acceleration

Rate of change of velocity.

Newton's First Law

An object remains at rest or in motion unless acted upon.

State of Rest

Condition where an object is not moving.

State of Motion

Condition where an object is moving.

Direction of Force

Path along which a force acts.

Magnitude of Force

Strength or size of a force applied.

Resistance to Motion

Opposition an object offers to changes in its state.

Examples of Inertia

Dust detaching from carpet when beaten.

Examples of Balanced Forces

Pushing a brick equally from both sides.

Examples of Unbalanced Forces

Brick moving towards greater applied force.

Effect of Balanced Forces

No change in object's motion or rest.

Effect of Unbalanced Forces

Change in object's motion or state.

Massive Objects

Require more force to change motion.

Light Objects

Require less force to change motion.

Force Application

Push or pull exerted on an object.

Velocity

Speed of an object in a given direction.

Newton's Laws

Fundamental principles governing motion.

Activity Demonstration

Experiments illustrating principles of forces.

Physical Examples

Real-world instances of force applications.

Newton's First Law

An object remains at rest or uniform motion unless acted upon.

Inertia

The resistance of an object to change its state of motion.

Law of Inertia

Another name for Newton's first law of motion.

Example of Inertia

Passengers fall backward when a bus accelerates.

Example of Inertia

Passengers fall forward when a bus stops suddenly.

Dust Detachment

Dust particles detach when a carpet is beaten.

Momentum Formula

p = mv, where p is momentum.

SI Unit of Momentum

Kilogram-metre per second (kg m s-1).

Direction of Momentum

Same as the direction of velocity.

Newton's Second Law

Force equals rate of change of momentum.

Force and Momentum Relationship

Force is proportional to change in momentum.

Force and Acceleration Relationship

Force also relates to mass and acceleration.

Constant Force

Force applied consistently over time changes momentum.

Change in Momentum

Difference between final and initial momentum.

Initial Momentum

Momentum before force is applied, p1 = mu.

Final Momentum

Momentum after force is applied, p2 = mv.

Rate of Change of Momentum

Change in momentum over time interval.

Proportionality Constant

k in F = k(p2 - p1)/t.

Velocity Change

Difference between final and initial velocities.

Mass in Motion

Mass influences the force needed to change velocity.

Unbalanced Force

Force that causes a change in motion.

Applications of First Law

Explains everyday phenomena like motion of passengers.

Force

A push or pull on an object.

Newton

Unit of force; symbol N.

Second Law of Motion

F = ma; relates force, mass, and acceleration.

Unit of Force

Defined as producing 1 m/s² acceleration on 1 kg.

Constant k

Value that simplifies force equation to F = ma.

1 Newton

Force causing 1 m/s² acceleration on 1 kg mass.

Catching a Cricket Ball

Fielder moves hands back to reduce force.

Falling on Cement

High force due to rapid momentum change.

Falling on Sand

Lower force due to longer momentum change time.

Karate Player's Strike

Quick momentum change delivers high force.

String Breaking

Quick lift causes high force, breaking string.

Example 10.1

15 N force on 3 kg produces 5 m/s².

Example 10.2

50 kg mass at 5 m/s² requires 250 N force.

Momentum

Product of mass and velocity.

Jumping from a Boat

Backward force on boat causes it to move.

Air Escape from Balloon

Balloon moves opposite direction of escaping air.

Force Calculation

F = ma; used to find unknown forces.

Force Exerted

Force applied by an object during interaction.

Interaction Pair

For every action, there is an equal reaction.

Action Force

Force exerted by one body on another.

Reaction Force

Force exerted by the second body back.

Newton's Third Law

For every action, there is an equal reaction.

Equal Magnitude

Action and reaction forces are equal in strength.

Opposite Direction

Action and reaction forces act in opposite ways.

Two Different Bodies

Action and reaction forces act on separate objects.

Simultaneous Forces

Action and reaction occur at the same time.

Balanced Forces

Equal forces acting on the same body cause no movement.

Momentum Conservation

Total momentum remains constant without external forces.