physics

• What does Newton's first law state about a body at rest or in motion?

  A body will remain at rest or move with constant velocity unless acted on by a resultant force.
• What does it mean for an object to be in translational equilibrium?

  It means the resultant force on the object is 0.
• How is the resultant force defined?

  The resultant force is the vector sum of all forces acting on an object.
• What does Newton's second law state about resultant force and acceleration?

  The resultant force of an object is directly proportional to its acceleration.
• What is the formula for Newton's second law?

  F = ma
• In which direction does acceleration act when a resultant force is applied?

  Acceleration acts in the same direction as the resultant force.
• What happens to an object's direction if the resultant force acts at an angle to its motion?

  The object will change direction.
• What does it mean if the resultant force acts in the direction of an object's motion?

  The acceleration will be positive.
• What does it mean if the resultant force acts in the opposite direction of an object's motion?

  The acceleration will be negative.
• What does Newton's third law state?

  Every action has an equal and opposite reaction.
• What are third-law pairs?

  They are the forces involved in interactions between two objects that arise in pairs.
• What are the characteristics of a Newton's third law force pair?

  Same type of force, same magnitude, opposite direction, acting on different objects.
• What is a contact force?

  A force that acts between two objects which are physically touching.
• What is surface friction?

  It is a force that opposes motion between two bodies in contact.
• How does friction transfer energy?

  Friction transfers energy by heating, which raises the temperature of the surroundings.
• In what direction does friction always act?

  Friction always acts in a direction parallel to the plane of contact.
• What is static friction?

  Static friction occurs when a body is stationary on a surface and matches any push or pull force until movement begins.
• How does static friction behave as a force is applied?

  Static friction increases in magnitude until movement begins and dynamic friction occurs.
• What is the maximum value of static friction compared to dynamic friction?

  The maximum value of static friction is larger than that of dynamic friction.
• What is the formula for static friction?

  Ff ≤ μs Fn
• What is dynamic friction?

  Dynamic friction occurs when a body is in motion on a surface and remains constant for a constant pushing force.
• What is the formula for dynamic friction?

  Ff = μd Fn
• What do μs and μd represent?

  μs is the coefficient of static friction, and μd is the coefficient of dynamic friction.
• What is the range of the coefficient of static friction?

  The coefficient of static friction is a number between 0 and 1, not including those numbers.
• How does the coefficient of static friction affect the movement of two objects?

  The larger the coefficient of static friction, the harder it is to move the two objects past each other.
• What is the difference between static and dynamic friction in terms of force value?

  Static friction has an increasing force value, while dynamic friction has a definite force value for a given situation.
• What is fluid resistance or viscous drag?

  It is the frictional force between an object and a fluid that opposes the motion between the object and the fluid.
• What is Stoke's law?

  Fd = 6πηrv
• What do η, r, and v represent in Stoke's law?

  η is fluid viscosity, r is the radius of the sphere, and v is the velocity of the sphere through the fluid.
• What is viscosity of a fluid?

  Viscosity is the thickness of a fluid.
• What is the coefficient of viscosity?

  It indicates how much a fluid will resist flow.
• How is the rate of flow of a fluid related to its viscosity?

  The rate of flow of a fluid is inversely proportional to its viscosity.
• What factors affect the size of the drag force?

  The size of the drag force depends on the speed, size, and shape of the object.
• What happens at terminal speed?

  Forces are balanced: weight of the sphere equals drag force equals buoyancy force.
• What is the formula for buoyancy?

  Fb = ρVg
• What do ρ, V, and g represent in the buoyancy formula?

  ρ is density, V is volume of the fluid being displaced, and g is acceleration of free fall.
• What is linear momentum?

  Linear momentum is the momentum of an object moving in only one dimension.
• When does momentum remain constant?

  Momentum remains constant unless acted on by an external resultant force.
• What is the formula for momentum?

  p = mv
• What does it mean that momentum is always conserved?

  The total linear momentum before a collision is equal to the total linear momentum after a collision unless acted on by an external force.