Forces and Motion Flashcards

A set of 60 vocabulary flashcards covering basic force concepts, contact and non-contact forces, agents and receivers, combining forces, balanced and unbalanced forces, F=ma, gravity, mass vs weight, friction, and application scenarios based on the lecture notes.

Force

A push or pull that can change an object's movement or shape.

Contact Force

A force that requires objects to touch in order to act.

Non-Contact Force

A force that can act on an object without the objects physically touching.

Agent

The object causing the force in a force interaction.

Receiver

The object receiving the force in a force interaction.

Net Force

The overall force on an object after all the forces acting on it have been combined.

Balanced Forces

Forces acting on an object that are equal in size and opposite in direction, resulting in a net force of $0\,\text{N}$.

Unbalanced Forces

Forces that do not cancel each other out, resulting in a net force that changes an object's motion.

$$F = ma$$

The formula connecting force ($F$), mass ($m$), and acceleration ($a$).

Acceleration

A change in velocity, such as speeding up, slowing down, or changing direction.

Newton ($\text{N}$)

The unit used to measure force and weight.

Gravity

A non-contact force that pulls objects towards the centre of Earth or towards another planet.

Mass

The amount of matter in an object, measured in kilograms ($\text{kg}$).

Weight

The force of gravity acting on an object's mass, measured in Newtons ($\text{N}$).

Kilograms ($\text{kg}$)

The unit used to measure mass.

Friction

A contact force that occurs when surfaces are touching and moving or trying to move against each other, opposing their motion.

Grip

The control and traction provided by friction between surfaces, enabling walking, holding objects, or stopping vehicles.

Chalk (in Gymnastics)

A substance used by gymnasts to increase friction and grip between their hands and equipment.

Lubricant

A substance such as oil that reduces friction between surfaces to allow them to slide across each other more easily.

Drag

Resistance experienced by objects moving through fluid, such as water resistance acting against a swimmer.

Upward Support Force

The force provided by a surface (like a table) that balances the downward pull of gravity on a stationary object.

Air Resistance

A force that acts against the motion of an object as it moves through the air, such as on a cyclist who stops pedalling.

Force Detection Signs

Observable evidence that a force is acting on an object, such as speeding up, slowing down, changing direction, or bending.

Magnetic Force Example

A non-contact force demonstrated when a magnet attracts a paperclip without touching it.

Pushing a Box Example

A contact force because a hand has to touch the box to push it.

Combining Forces in the Same Direction

Combining two forces that act the same way to produce a larger overall force.

Subtracting Opposite Forces

Subtracting the smaller force from the larger force when two forces act in opposite directions.

Zero Net Force Motion State

The condition where an object is either stationary or moving at a constant speed in a straight line.

Initiating Motion on a Stationary Object

Applying an unbalanced force to cause a still object, such as a football, to start moving.

Force and Acceleration Relationship

An increase in applied force to the same object resulting in an increase in its acceleration.

Mass Effect on Acceleration

The principle that a larger mass requires more force to produce the same acceleration as a smaller mass.

Smaller Mass Acceleration

When two objects experience the same force, the object with the smaller mass accelerates more.

Planet Mass and Gravity

The relationship where the mass of a planet determines how strongly its gravity pulls objects.

Mass Constancy Across Planets

The property of mass remaining the same when traveling to another planet.

Weight Change Mechanism

The variation in an object's weight caused by changes in gravitational strength while mass remains constant.

Stronger Gravity Effect on Weight

An increase in gravitational strength causing an object's weight to increase.

Weaker Gravity Effect on Weight

A decrease in gravitational strength causing an object's weight to decrease.

Helpful Friction

Friction that gives us grip, allowing us to walk, hold objects easily, or stop vehicles.

Problematic Friction

Friction that slows objects down and causes energy to be transferred as heat.

Ice Surface Grip

A state with very little friction where shoes have less grip, making running or walking difficult.

Oiled Metal vs Sand Friction

A comparison showing that oiled metal provides much less friction for smooth sliding, while sand creates more resistance.

Reasons Not to Minimize Friction

The practical necessity of keeping some friction to maintain grip and control.

Swimmer Efficiency

Reducing friction and drag so that swimmers experience less resistance from water and move more efficiently.

High Friction Need Scenario

A real-life situation where increased friction is desired, such as shoes gripping the ground.

Low Friction Need Scenario

A real-life situation where reduced friction is desired, such as skis sliding over snow.

Lunar Gravity Effect on Mass

An astronaut's mass staying completely the same when traveling to the Moon.

Lunar Gravity Effect on Weight

An astronaut's weight and gravitational force decreasing on the Moon due to weaker gravity.

Balanced Forces on a Moving Car

A scenario where a car travels forwards at a constant speed in a straight line because all forces acting on it are balanced.

Force Applied Opposite to Motion

A leftward force on a rightward-moving ball causing it to slow down, stop, or reverse direction to the left.

Methods to Reduce Friction on a Floor

Making surfaces smoother or applying a lubricant such as oil to make a box slide more easily.

Effect of Surface Roughness

Creating more friction by making a surface rougher, which opposes an object's motion and makes it harder to move.

Direction of Net Force Movement

The direction taken by an object pushed in opposite directions, determined by the direction of the larger force.

Non-Contact Reach of Gravity

Gravity acting on objects on or near Earth, including objects suspended in the air.

Force Acting Without Movement

A scenario where forces act on an object (such as gravity on a book) without making it move because another force balances it.

Football Kick Agent

The foot causing the force when kicking a football.

Football Kick Receiver

The football receiving the force when kicked by a foot.

Object Role Flexibility

The ability of an object to serve as an agent in one situation and a receiver in another, depending on whether it causes or receives force.

Variables in $F = ma$

The three physical parameters connected by Newton's formula: force, mass, and acceleration.

Double Force on Identical Shopping Carts

Applying twice as much force to one identical shopping cart, causing it to accelerate more because acceleration increases with force.

Contact Force Identification Criterion

Determining force classification by asking whether objects must touch for the force to act.