15.1 Forces and Elasticity

• A force is a vector quantity because it has both magnitude and direction
• What is the relative strength of the gravitational force?

  1
• What force is responsible for maintaining nuclear stability?

  Strong Nuclear
• What is the magnitude of the reaction force in Newton's Third Law compared to the action force?

  Equal
• Vector quantities have both magnitude and direction
• What are the four fundamental forces in physics?

  Gravitational, electromagnetic, strong nuclear, weak nuclear
• The gravitational force has infinite range.


  True
• The action force in Newton's Third Law is the force exerted by one object on another
• What is an example of an inelastic material?

  Clay
• What does the spring constant 'k' represent in Hooke's Law?

  The stiffness of the material
• What does the elastic limit on a force-extension graph indicate?

  The point beyond which permanent deformation occurs
• In the proportional region of the force-extension graph, the force is directly proportional to the extension or compression.

  True
• The break point on a force-extension graph is where the material can no longer support any load.


  True
• Match the type of fundamental force with its definition:

  Gravitational Force ↔️ Attraction between objects with mass

  Electromagnetic Force ↔️ Interaction between charged particles

  Strong Nuclear Force ↔️ Holds protons and neutrons together

  Weak Nuclear Force ↔️ Responsible for radioactive decay
• What is the definition of an action force in Newton's Third Law?

  The force exerted by one object on another
• What does Newton's Third Law of Motion state?

  For every action, reaction
• Action and reaction forces have the same magnitude.

  True
• Elastic materials fully recover their original shape when stress is removed
• Match the property with the material type:

  Temporary deformation ↔️ Elastic materials

  Permanent deformation ↔️ Inelastic materials
• The spring constant in Hooke's Law is measured in N/m
• What does the proportional region in a force-extension graph represent?

  Hooke's Law applies
• Order the key features of a force-extension graph:

  1️⃣ Proportional region

  2️⃣ Elastic limit

  3️⃣ Yield point

  4️⃣ Break point
• Hooke's Law can be expressed as $F =$$kΔx$, where $k$ represents the spring constant.
• In the formula $k =$$\frac{F}{\Delta x}$, $F$ is measured in newtons.
• What is the stage in plastic deformation where localized thinning occurs before failure?

  Necking
• Match the type of force with its definition:

  Gravitational ↔️ Attraction between objects with mass

  Electromagnetic ↔️ Interaction between charged particles

  Strong Nuclear ↔️ Holds protons and neutrons in the nucleus

  Weak Nuclear ↔️ Responsible for radioactive decay
• Action and reaction forces act on the same object.

  False
• What is the SI unit of force?

  Newton (N)
• Match the type of force with its definition:

  Gravitational ↔️ Attraction between objects with mass

  Electromagnetic ↔️ Interaction between charged particles

  Strong Nuclear ↔️ Holds protons and neutrons

  Weak Nuclear ↔️ Responsible for radioactive decay
• The electromagnetic force holds atoms and molecules together.


  True
• Newton's Third Law states that for every action, there is an equal and opposite reaction.


  True
• Action and reaction forces act on the same object.

  False
• The SI unit of force is the Newton
• What is the primary role of the strong nuclear force?

  Holds protons and neutrons in the nucleus
• Newton's Third Law states that for every action, there is an equal and opposite reaction.


  True
• Elasticity is the ability of a material to deform under stress and return to its original shape when the stress is removed
• Hooke's Law states that the force required to stretch or compress an elastic material is directly proportional to the amount of stretch
• The origin on a force-extension graph represents the zero point for both force and extension
• The force-extension graph is a graphical representation of Hooke's Law
• What happens to a material at the yield point on a force-extension graph?

  It deforms permanently