2.3. Dynamics

• Inertia is the tendency of an object to resist changes in its state of motion
• Acceleration is the rate of change of velocity
• Unlike kinematics, dynamics focuses on the causes of motion
• Action and reaction forces in Newton's Third Law act on the same object

  False
• Match the action force with its corresponding reaction force:

  Force exerted by object A on object B ↔️ Force exerted by object B on object A

  Equal in magnitude ↔️ Equal in magnitude

  Opposite in direction ↔️ Opposite in direction
• Steps to construct a free body diagram:

  1️⃣ Draw the object as a simple shape

  2️⃣ Identify all the forces acting on the object

  3️⃣ Draw the forces as arrows in the appropriate direction

  4️⃣ Label each force with its type
• What are the three primary equations of motion for objects moving with constant acceleration?

  v = u + at ||| s = ut + ½at² ||| v² = u² + 2as
• Momentum is calculated as the product of mass and velocity
• Dynamics allows us to analyze and predict the behavior of moving objects by considering the forces acting on them
• The key factors in dynamics are forces and mass
• What is the net force on an object in equilibrium?

  Zero
• Newton's Third Law states that action and reaction forces act on the same object.

  False
• Steps to construct a free body diagram

  1️⃣ Draw the object as a simple shape

  2️⃣ Identify and add all forces

  3️⃣ Label each force with its type
• A car starts from rest and accelerates at 2 m/s² for 5 seconds. What is its final velocity?

  10 m/s
• Impulse and momentum are related concepts.


  True
• Match the concept with its formula:

  Impulse ↔️ $J =$$FΔt =$$Δp$

  Momentum ↔️ $p =$$mv$
• Momentum is calculated as the product of mass and velocity.

  True
• What are the final momenta of two objects after a collision in a closed system called?

  $p'_{1}$ and $p'_{2}$
• In static equilibrium, both net force and velocity are zero.


  True
• When the net force is zero, the acceleration is also zero
• Dynamics is the branch of physics that deals with the motion of objects and the forces that cause that motion
• What is the net force acting on a 1000 kg car accelerating at 2 m/s²?

  2000 N
• What equation summarizes Newton's Second Law of Motion?

  F = ma
• Newton's Third Law of Motion states that for every action force, there is an equal and opposite reaction force.reaction
• When you push against a wall, the wall pushes back on you with an equal and opposite force
• Free body diagrams help simplify complex dynamics problems by breaking down the forces into their individual components
• A car accelerating from rest at 2 m/s² for 5 seconds will have a final velocity of 10 m/s.

  True
• A ball hit by a bat with a force of 100 N for 0.02 seconds experiences an impulse of 2 N⋅s.


  True
• Kinematics focuses on the causes of motion, while dynamics describes motion itself.

  False
• What is the purpose of a free body diagram?

  Analyze the motion
• Momentum is calculated as mass multiplied by velocity
• Momentum is a measure of an object's mass in motion
• What is the unit of impulse?

  Newton-seconds (N⋅s)
• What does the conservation of momentum state?

  Total momentum remains constant
• In the example, the initial momentum of the first object is m$_{1}$
• Match the type of equilibrium with its velocity:

  Static Equilibrium ↔️ Zero

  Dynamic Equilibrium ↔️ Constant
• What key principles of dynamics are applied when driving a car?

  Newton's Laws
• Newton's First Law of Motion is also known as the Law of Inertia


  True
• What are the two types of equilibrium according to Newton's First Law?

  Static and dynamic
• The action and reaction forces in Newton's Third Law always act on the same object.

  False