unit 2,3,4

• what is vector and scalar quantities

  scalar is only magnitude while vector is magnitude + direction
• speed formula


  s = d/t
• what is speed


  the rate at which an object's position changes
• what is velocity


  the rate of change of displacement of a body with respect to time
• velocity formula


  s = displacement/time
• what is acceleration


  the rate of change of velocity of an object with respect to time
• acceleration formula


  acceleration = change in velocity/time
• what is displacement


  the change in an objects position or the difference of final and initial positions of an object in a given interval of time
• displacement formula


  displacement = s x t
• In a D-T graph, finding the gradient will give you speed on the object
• In a V-T graph, finding the area below the graph will give you the total distance covered by the object
• what device is used to measure force and how does it work

  a Newton meter - contains a spring connected to a metal hook, the spring stretches as a force is applied to the hook.
• what does newtons first law state

  tendency of an object in motion to stay in motion, or an object to stay at rest to remain at rest unless acted upon by a force. This is also known as Inertia so as the mass increases the tendency to resist change also increases.
• what do newtons second law state (equation)

  The more force you apply to an object, the faster it will accelerate, and the heavier the object is, the less it will accelerate for the same amount of force. F = ma
• what does newtons third law state

  For every action, there is an opposite and equal reaction
• what is momentum + equation

  it is when an object with a specific mass is set in motion. The greater the mass the greater the momentum P = m x v
• what is impulse + equation


  it is the force applied on an object during a certain duration of time.

  impulse = force x change in time
• what is mass


  • amount of matter in an object

  • stays constant no matter where in the universe the object is place

  • measured in kilograms (kg)
• what is weight


  • force applied on an object due to gravity

  • weight can fluctuate depending on where in the universe the object is placed

  • measured in newtons (N)
• equation linking weight mass and gravity


  W = m x g
• What does the HOOKES LAW explore

  the relationship between the force applied to a spring and the resulting extension or compression of the spring keeping in mind the springs constant (type of wire/thickness)
• formula for hookes law


  F = k x e OR force = springs constant x extension
• what is stopping distance

  total distance traveled from when the driver first spots the hazard to when the car stops
• thinking distance + braking distance = stopping distance
• what is thinking distance


  the distance the car travels during the driver's reaction time
• what is braking distance


  distance the car travels from where the brakes are first applied to when the car stops
• thinking distance = vehicle speed x reaction time
• factors affecting thinking distance

  • speed - the faster the car the further you will travel

  • drivers reaction time - vary between people (tired, drunks, distracted, drugs)
• factors affecting braking distance

  • condition/quality of the brakes - worn our so won't slow down as quickly so breaking distance increases

  • traction between car and road - less friction between the tires and the road is icy or wet so tire cannot grip the road
• thinking distance = vehicle speed x reaction time
• force x braking distance = 1/2mv^2
• what are four safety precautions in cars

  • air bag

  • crumple zone

  • seat belt

  • head restraint
• pressure in liquids increases with depth and it depends on the density of the liquid. higher density = higher pressure
• in solids, the smaller the surface area the greater the pressure
• equation for pressure

  pressure = force x area
• what is density

  the measure of how compact the mass in a substance is
• equation of density

  density = mass x volume OR f=m/v
• pressure in gas

  • changing the volume = more collisions

  • changing the temperature = gains KE and more collisions

  • changing the number of particles = concentration increases and more collisions
• pressure is inversely proportional to collision frequency
• what is work

  a force causing an object to move