P5- Forces

• What does a vector have that a scalar does not?

  Direction
• Why can scalars generally not be negative?

  They only have magnitude, no direction
• What is the scalar quantity for distance?

  Distance
• What is the vector quantity for distance?

  Displacement
• What is the scalar quantity for time?

  Time
• What is the vector quantity for acceleration?

  Acceleration
• What is the vector quantity for force?

  Force
• What is the scalar quantity for mass?

  Mass
• What is the vector quantity for momentum?

  Momentum
• What is the scalar quantity for energy?

  Energy
• What happens to the displacement of a ball thrown off a cliff at the height of the cliff?

  Displacement is 0 at the height
• How can you define the "0" point of a vector in long answer questions?

  You can set it at any reference point
• When is speed considered velocity?

  When a direction is given
• What happens to a car traveling around a roundabout at constant speed?

  Its velocity is constantly changing
• What is a force?

  A push or pull on an object
• How can vectors be represented visually?

  By arrows indicating magnitude and direction
• What are the two types of forces based on contact?

  Contact and non-contact forces
• What does the gravitational field do?

  Attracts all other matter
• How does mass affect gravitational attraction?

  Larger mass creates stronger attraction
• What is weight?

  Force exerted on mass by gravity
• What is the formula for weight?

  W = mg
• What units are used for weight and mass?

  Weight in newtons, mass in kilograms
• How is weight measured?

  By a force meter or calibrated spring-balance
• What is the value of g on Earth?

  9.8 m/s²
• How does weight change on different planets?

  Weight varies due to different gravitational strengths
• What is the acceleration in free fall due to gravity?

  It is equal to g, i.e., 10 m/s²
• Where does the weight of an object act?

  At the object's center of mass
• What is a resultant force?

  Sum of all forces acting on an object
• How do you find the resultant force when multiple forces act along a straight line?

  Add or subtract the forces accordingly
• What forces act on a skydiver?

  Air resistance and weight
• What happens to the resultant force as a skydiver falls?

  It decreases as air resistance increases
• What is terminal velocity?

  When resultant force is zero, no acceleration
• What do free body diagrams show?

  Forces and their directions acting on an object
• How can a force at angle θ be resolved?

  Into components parallel and perpendicular to the ground
• What is the formula for work done?

  W = Fs
• What units are used for work done, force, and distance?

  Joules, newtons, and meters
• When is work done on an object?

  When energy is transferred to another form
• What is one joule of work done equivalent to?

  One newton causing one meter displacement
• What happens when work is done against frictional forces?

  It causes a rise in temperature of the object
• What is deformation?

  Changing the shape of an object