motion c5

• Scalar


  Quantities with magnitude only, no direction, magnitude cannot be negative
• Vector


  Quantities with both magnitude and direction, magnitude can be negative or positive
• newton’s first law: an object will remain at rest or continue to move at a constant speed unless acted upon by a resultant force
• first law of motion: law of inertia
• acceleration due to gravity is 9.81 m/s2
• vectors are measured head to tail
• to convert km/h to m/s, divide by 3.6
• to convert m/s to km/h multiply by 3.6
• newton’s second law: the acceleration of an object is directly proportional to the resultant force acting on it
• second law of motion: f = ma
• f = m x (v - u / t)
• in displacement time graphs:

  velocity is the gradient
• s = displacement
• d = distance
• air resistance is the same as drag
• distance is always in metres

  speed/velocity is always m/s

  time is always in seconds
• when time is longer, acceleration decreases.

  when acceleration decreases, less force is required to move mass.
• what do u do when u first see a question?

  LIST ALL YOUR EQUATION OF MOTION VARIABLES
• state of motion includes speed and direction
• newton‘s third law: for every action there is an equal and opposite reaction
• third law of motion: action reaction
• in velocity time graphs:

  acceleration is the gradient
• in acceleration time graphs:

  straight line means no acceleration and velocity is constant
• in displacement time graphs:

  flat line means object is stationary
• in velocity time graphs:

  linear gradient means constant acceleration
• in velocity time graphs:

  x intercept means object has stopped moving > zero velocity!
• in displacement time graphs:

  x intercept means object has travelled back to origin
• in acceleration time graph:

  x intercept means velocity is constant
• in acceleration time graph:

  negative acceleration below x axis means object is accelerating in the opposite direction
• in velocity time graph:

  area under graph is total distance travelled
• in acceleration time graph:

  area under graph is change in velocity
• in velocity time graphs:

  to find displacement = area above x axis - area under x axis
• projectile motion?


  horizontal velocity is constant

  vertical velocity accelerates
• in acceleration time graph:

  positive acceleration below the x axis means the object is decelerating in the opposite direction
• angles of total velocity in projectile motion are measured below the horizontal
• Fnet = larger F - smaller F
• include direction in your vector answers
• how many significant figures?

  3
• times 10^-x means?

  number is smaller, decimal point moves left
• times 10^x means?

  number is bigger, decimal point moves right