Contact Forces

contact force

a push or pull that occurs when two objects are touching each other.

newton (N)

unit for measuring force

elastic limit

the maximum force to which a material can be stretched or compressed and still go back to its original shape without permanently deforming. Beyond the point, the object is permanently deformed.

elasticity

the ability of a material to return to its original shape after being stretched, compressed, or deformed.

breaking point

the point at which a material can no longer withstand an applied force and permanently deforms or fractures. Beyond this point, the object is considered broken and unusable.

friction

a force that opposes the motion of an object when two surfaces rub against one another. This force produces heat.

air resistance

a force that can either oppose motion or speed up motion depending on if it is a headwind or tailwind.

free body diagram

a diagram in which a single object or subsystem is drawn with arrows showing the relative forces acting on the object.

kinetic energy

the energy that an object possesses due to its motion. The formula is KE = 1/2(mass) x (velocity)²

potential energy

stored energy that an object possesses due to its position or state. It can be converted to kinetic energy.

speed/ velocity

the rate at which an object moves in a particular direction.

mass

the amount of matter in an object, typically measured in kilograms.

direct relationship

where an increase in one variable results in an increase in the other.

indirect relationship

where an increase in one variable results in a decrease in the other.

independent variable

a variable that is manipulated or purposely changed in an experiment to observe its effect on the dependent variable.

dependent variable

a variable that is measured and recorded in an experiment to assess the effect of changes in the independent variable.

controlled variable

a variable that is kept constant throughout an experiment to ensure that any changes in the dependent variable are solely due to the manipulation of the independent variable.

deformation

the change in shape or size of an object due to applied forces.

Newton’s Third Law

states that for every action, there is an equal and opposite reaction, meaning forces always occur in pairs.

linear

a graphical function that can be represented by a straight line, often indicating a direct proportionality between two variables.

non-linear/ exponential

a graphical function that cannot be represented by a straight line, but is curved, often indicating a variable that changes at a varying rate.

cushioning material

substances designed to absorb shock and reduce impact forces in various applications.

peak force

the maximum force experienced by a material or object during an impact or compression event.

spring scale

a device used to measure the force exerted by an object, typically using a spring that stretches in response to the force applied.