forces

• What is the definition of an elastic body?

  An elastic body returns to its original shape
• What happens to an inelastic body when force is removed?

  It does not return to its original shape
• What does extension refer to in the context of springs?

  Increase in length when stretched
• How is the force on a spring calculated according to Hooke's Law?

  F(N) = k(N/m) x e(m)
• What does a higher spring constant indicate?

  Stiffer spring requiring more force to stretch
• What is the relationship between force and extension in Hooke's Law?

  They are directly proportional
• What is the elastic limit?

  Point where object returns to original shape
• What occurs during deformation?

  Object will not return to original shape
• What is the formula for elastic potential energy?

  E = ½ x k x e²
• What does a moment represent in physics?

  Rotational turning effect of a force
• How is the moment calculated?

  Moment = d x f
• What is the effect of distance on the moment of a force?

  Greater distance increases the moment
• What are the key concepts related to moments in levers and gears?

  • Levers transmit turning effects of forces
  • Forces on the same side of the pivot act in the same direction
  • Closer force to pivot results in larger effect
  • Gears transmit turning effects
• What is the formula for calculating elastic potential energy in a spring?

  E = ½ x k x e²
• If a force of 500N is applied at a distance of 0.1m, what is the moment?

  Moment = 50Nm
• How do moments differ when forces act in opposite directions?

  They can cancel each other out
• What is the unit of moment in physics?

  Newton meter (Nm)
• What is the significance of the pivot in a lever?

  It is the point around which moments act
• If a gear transmits a turning effect, what is its primary function?

  To change the direction of force
• How does the distance from the pivot affect the force needed to lift an object?

  More distance requires less force to lift
• What is the relationship between force and distance in moments?

  Force multiplied by distance gives moment
• What happens to the moment if the force is doubled while the distance remains the same?

  The moment also doubles
• If a force of 1200N is applied at a distance of 1.6m, what is the moment?

  Moment = 1920Nm
• How do levers and gears function in terms of force transmission?

  They transmit and amplify turning effects
• What is the effect of an ice cube's position relative to the pivot in a lever?

  Closer to the pivot results in larger force
• How do gears affect the speed of rotation?

  They can increase or decrease speed
• If a lever has a force of 500N acting at a distance of 2m, what is the moment?

  Moment = 1000Nm
• What is the relationship between the direction of forces and the moment they create?

  Opposite directions can cancel moments
• pressure is the force of unit per area, the pressure in fluids causes a force normal to the surface and acts at a right angle
• pressure increases as the depth increases , the pressure in a liquid is due to the weight of the column of the water above
• calculating pressure on a liquid

  • pressure - height x density x gravitational field
• atmospheric pressure - atmosphere is thin compared to the size of the earth and becomes less dense as the altitude increases
• atmospheric pressure decreases as the height of the surface above ground level increases as the altitude increases : the number of air molecules decreases, weight of air decreases, less air above a surface
• speed and distance are scalar

  velocity and displacement are vector
• the rate of change of velocity - the amount that velocity changes per unit time
• change in velocity = final velocity - initial velocity
• acceleration = change in velocity / time taken
• terminal velocity - the maximum speed of an object, reached when the forces moving the object are balanced by its friction forces
• the object moves at a steady speed in a constant direction because of the resultant force acting is 0
• three stages as an object falls through a fluid

  • at the start the object accelerates downwards due to gravity
  • as the object's speed increases, frictional forces such as air resistance or drag increase
  • at terminal velocity the weight of the object due to gravity is balanced by the frictional forces and the resultant force being 0