physics paper 2

• Force is a


  vector quantity
• What do vectors have

  Direction and magnitude. Force, velocity, displacement, acceleration, momentum
• What do scalar have

  Direction. Speed, distance, mass, temperature, time
• A force can be a


  push or a pull
• When two objects have to be touching for a force to act,


  that force is called a contact force.
• If the objects do not need to be touching for the force to act,

  the force is a non-contact force.
• Name some contact forces

  Friction, air resistance
• Name some non-contact forces

  Magnetic, gravitational, electrostatic
• What is weight?


  The force acting on an object due to gravity.
• What is the resultant force?

  It is the forces combined to show the result of the overall force.
• When a force moves an object through a distance,

  energy is transferred and work is done.
• If forces acting on an object combine to give a resultant force of zero:

  the object is in equilibrium.
• If a object is elastically deformed


  it can go back to it's original shape and length after the force has been removed.
• An object has been inelastically deformed


  if it doesn't return to it's original shape and length after the force has been removed.
• What is the spring constant?

  How stiff the spring is, the stiffness depends on the material used.
• On a spring constant graph, what does a curve show?

  It shows the extension is no longer proportional to force.
• The point where the extension is no longer proportional to the force is the

  limit of proportionality
• Work done in stretching a spring can be found using this equation:

  E = 1/2 x ke^2 or Elastic potential energy - 1/2 spring constant / extenstion^2
• Speed is


  how fast you're going with no regard to the direction.
• Velocity is


  a speed in a given direction
• Acceleration is the


  change in velocity in a certain amount of time.
• Constant acceleration is sometimes called

  uniform acceleration.
• Velocity-time Graph


  Gradient = Acceleration,

  Flat sections = Steady speed,

  Steeper the graph = Greater the acceleration

  A curve means changing acceleration.

  The area under the graph is equal to the distance travelled.
• What can reduce friction?

  Lubcricant
• What is drag?


  The resistance you get in gas or luquid.
• What does a fluid represent?

  A gas or a liquid
• What is the best way to reduce Drag,

  steamlining the object.
• What does steamlined mean?


  This is where the object is designed to allow fluid to flow easily across it, reducing drag.
• Objects with large surface areas tend to have

  lower terminal velocities.
• What is Newton's First Law?

  If the resultant force on a stationary object is zero, the object will remain stationary. If the resultant force on a moving object is zero, it'll just carry on moving at the same velocity.
• Acceleration is


  inversely proportional to the mass of the object.
• What is the formula for Newton's second law?


  F = ma, Resultant force (N) = Mass (kg) x Acceleration (m/s^2)
• What is inertia?


  This is the tendency to continue in the same state of motion.
• A objects inertial mass


  measures how difficult it is to change the velocity of an object.
• To find the inertial mass you use

  m = F / a
• Newton's Third Law says:


  When two objects interact, the force they exert on each other are equal and opposite.
• If two people push on each other,

  the person will the smaller mass will move further due to a = F / m
• Stopping distance =


  Thinking Distance + Breaking Distance
• What is the Thinking Distance?


  The distance travels during the driver's reaction time.
• What is the Breaking Distance?

  The distance taken to stop under the breaking force.