Year 10 Spring Check-In - motion and forces

Scalar Quantity

A physical quantity that has only magnitude (size) but no direction (e.g., speed, distance, mass, energy)

Vector Quantity

A physical quantity that has both magnitude and direction (e.g., velocity, displacement, force)

Distance

The total path length traveled by an object, a scalar quantity

Displacement

The shortest distance from the initial to the final position, a vector quantity

Speed

The rate of change of distance with respect to time; calculated using the equation: Speed = distance/time

Velocity

The rate of change of displacement with time (speed in a specific direction); calculated using the equation: Velocity = displacement/time

Acceleration

The rate of change of velocity over time; calculated using the equation: Acceleration = change in velocity/time

Uniform Acceleration

When acceleration is constant over time (e.g., free-fall under gravity); described by the equation: v^2 = u^2 + 2as

Force

A push or pull on an object due to interaction with another object, measured in newtons (N)

Contact Force

A force that acts when objects are touching (e.g., friction, tension)

Non-contact Force

A force that acts at a distance (e.g., gravity, magnetic force)

Newton's First Law

An object will remain at rest or move at a constant velocity unless acted upon by a resultant force

Newton's Second Law

The force acting on an object is equal to the mass times the acceleration; described by the equation: F = m × a

Newton's Third Law

For every action, there is an equal and opposite reaction

Weight

The force acting on a mass due to gravity; calculated using the equation: W = m × g

Mass

The amount of matter in an object, measured in kilograms (kg)

Friction

A force that resists the motion of objects sliding past each other

Air Resistance (Drag)

The force opposing motion through air, increasing with speed

Terminal Velocity

The constant speed reached when the force of air resistance equals the force of gravity on a falling object

Momentum

The product of an object's mass and velocity; calculated using the equation: p = m × v

Conservation of Momentum

In a closed system, the total momentum before a collision equals the total momentum after the collision

Elastic Collision

A collision in which both momentum and kinetic energy are conserved

Inelastic Collision

A collision in which momentum is conserved but kinetic energy is not

Moment

The turning effect of a force; calculated using the equation: Moment = force × perpendicular distance from pivot

Principle of Moments

For an object in equilibrium, the total clockwise moment equals the total anticlockwise moment

Levers

Simple machines that amplify force by rotating around a pivot

Gears

Rotating wheels with teeth that transmit and change the direction of force

Energy

The capacity to do work, measured in joules (J)

Kinetic Energy

The energy an object has due to its motion; calculated using the equation: E_k = 1/2 m v^2

Gravitational Potential Energy

The energy stored in an object due to its height above the ground; calculated using the equation: E_p = mgh

Work Done

The transfer of energy when a force moves an object over a distance; calculated using the equation: W = F × d, where W is work done (J), F is force (N), and d is distance moved in the direction of the force (m)

Power

The rate of doing work or transferring energy; calculated using the equation: P = W/t, where P is power (W), W is work done (J), and t is time (s)

Efficiency

A measure of how much useful energy is transferred; calculated using the equation: Efficiency = (useful energy output/total energy input) × 100

Conservation of Energy

The principle that energy cannot be created or destroyed, only transferred or transformed

Dissipation

The spreading out of energy into the surroundings, making it less useful

Energy Transfer Diagrams

Diagrams used to show how energy is transferred in a system, often including input, useful output, and wasted energy

Energy Stores

Different forms of stored energy, including kinetic, gravitational potential, elastic potential, chemical, thermal, nuclear, and magnetic

Energy Pathways

The ways in which energy is transferred between stores, including mechanical work, electrical work, heating, and radiation

Resultant Force

The single force that has the same effect as all the individual forces acting on an object combined

Stopping Distance

The total distance a vehicle travels from the moment the driver reacts to the moment the vehicle stops; calculated as: Stopping distance = thinking distance + braking distance

Thinking Distance

The distance traveled by a vehicle during the driver's reaction time

Braking Distance

The distance traveled by the vehicle after the brakes are applied until it comes to a stop

Factors Affecting Stopping Distance

Include speed, mass of the vehicle, road conditions (wet or icy surfaces), and tire or brake conditions

Reaction Time

The time taken for a driver to respond to a stimulus; affected by factors like fatigue, alcohol, drugs, and distractions

Force and Change in Momentum

The relationship between force, change in momentum, and time; described by the equation: F = Δp/t, where F is force (N), Δp is the change in momentum (kg·m/s), and t is the time over which the change occurs

Circular Motion

When an object moves in a circle at a constant speed, its velocity continuously changes due to a changing direction, resulting in centripetal acceleration

Centripetal Force

The resultant force that acts toward the center of a circle, keeping an object in circular motion; calculated using: F = mv²/r, where m is mass (kg), v is velocity (m/s), and r is the radius of the circle (m)

Gravitational Field Strength

The force acting per kilogram of mass due to gravity; on Earth, it is approximately 9.8 N/kg

Free-body Diagrams

Diagrams that show all the forces acting on an object, using arrows to represent the magnitude and direction of the forces

Balanced Forces

When the resultant force on an object is zero, meaning no acceleration occurs (object is stationary or moving at a constant velocity)

Unbalanced Forces

When the resultant force is not zero, causing acceleration or deceleration

Hooke's Law

The extension of a spring is directly proportional to the force applied, up to the elastic limit; described by the equation: F = k × e

Elastic Potential Energy

The energy stored in a stretched or compressed spring; calculated using: E_e = 1/2 k e²

Tension

The force transmitted through a rope, string, or cable when it is pulled tight by forces acting from opposite ends