Unit 1 mechanics (G481) motion

HideShow resource information
  • Created by: Elly
  • Created on: 02-01-13 10:15
View mindmap
  • Motion
    • scalars
      • a quantity with magnitude but not direction
      • e.g. potential difference, speed, pressure, distance
    • Free fall
      • g=9.81ms^-2
      • Trap door method
        • electromagnet just supports a steel ball
          • when current through the electromagnetis switched off theball starts to fall and the clock is triggered.
            • balls falls onto trap door
              • when trap  door breaks the clock is stopped.
                • distance of fall is measured and so is the time taken.
                  • Repeats
                    • electromagnet just supports a steel ball
                      • when current through the electromagnetis switched off theball starts to fall and the clock is triggered.
                        • balls falls onto trap door
                          • when trap  door breaks the clock is stopped.
                            • distance of fall is measured and so is the time taken.
                              • Repeats
          • theory
            • s=ut+1/2at^2 . u is 0 as ball starts from rest.
              • this gives s=1/2gt^2 and hence g=2s/t^2.
                • a graph of s against against t^2 will have a gradient of g/2.
          • Random uncertainty
            • em current too large cause a delay in releasing ball. current must only just support ball.
            • If distance is too large or ball to small air resistance may have a noticeable effect.
            • ensure that distance is measured accurately from base of ball to trap door not the electromagnet to door.
      • Vectors
        • resolving
          • horizontal and vertical components
        • Calculations
          • Trigonometry
            • the length of the hypotenuse AC is 55.0mm and angle next to right angle is 72*.
              • This makes the side adjacent to the angle         55.0xCos72*=17.0mm
              • and the side opposite to the angle  =55.0xSin72*=52.3mm
          • Pythagorus
            • A llorry's load hass a weight of 40000NN and it is being pulledd along by a horizontal force of 15000N what is the resultant of these two forces?
              • Resultant^2= (4.0x10^4)^2 + (1.5x10^4)^2 = 18.25x10^8 so resultant=4.27x10^4N
        • a quantity with both magnitude and direction
          • e.g. electric current, velocity, displacement, acceleration, force.
      • constant acceleration  equations
        • s u v a t
          • s = displacement
            • m
          • u =  initial velocity v= end  velocity
            • ms^-11
          • a = acceleration
            • ms^-2
          • t = time
            • s
        • v=u+at
        • s=1/2(u+v)t
        • s=ut+1/2at^2
        • v^2=u^2+2as
      • graphs of motion
        • Displacement-time  graphs
          • Gradient = velocity
        • velocity-time graphs
          • gradient  represents accelerration
          • Untitled
    • This makes the side adjacent to the angle         55.0xCos72*=17.0mm

    Comments

    Mrs Jones

    This is a great starting point and includes a lot of the major points.  I would use this as the basis for a revision session maybe print off and add some graphs of motion and some examples of resolving vector quantities (most common are force and acceleration) by diagram.

    Similar Physics resources:

    See all Physics resources »See all Motion resources »