3.2 Forces in action

Subdecks (2)

Cards (16)

  • Net Force, F = Mass * Acceleration
    Newton is defined as the force required to accelerate a 1 Kg mass by 1 ms^-2
  • Examples of Forces =
    Weight = m*g
    Friction
    normal force, (contact force)
    upthrust = in fluids
    Tension = in ropes
  • What is the resultant force?
    A) 17N to the right
  • Drag is proportional to V^2
    acceleration is not constant
    Factors affecting drag =
    Surface area
    Speed
  • Acceleration in a fluid:
    A) acceleration = m*g
    B) accelerating at a decreasing rate as drag increases
    C) Terminal velocity
  • Forces on a slope:
    A) Mg * sin(0)
    B) Mg*cos(0)
  • Centre of gravity is a point at which the entire weight of an object seems to act
    Centre of mass is a point at which the entire mass of an a object seems to act
  • The moment of a force is defined as the product of the force and the perpendicular distance from the pivot to the line of action
    Moment = Force * perpendicular distance
  • A force couple consists of two equal opposite forces acting in the same plane
    Torque = Force * distance
  • Triangle of forces is only applicable if object is in equilibrium
    A) No resultant force
  • Density is defined as mass per unit volume
    Density = mass/volume

    Pressure is defined as force per unit area
    Pressure = Force/area
  • Pressure in a fluid
    Density = mass/Volume
    A) Mass = D*v
  • Archimedes' Principle

    States that the upthrust acting on a body submerged in a liquid is equal to the weight of the liquid that has been displaced
    Upthrust = weight of water displaced , m*g
    therefore:
    Upthrust = Density * volume * g
  • Principle of Moments
    An object will be in equilibrium if:
    There is no net moment
    The sum of clockwise moments is equal to the sum of anticlockwise moments
    What is F2?
    A) 7.5N