Physics

• Speed is how fast an object travels with no regard to the direction.
• Velocity is an object travelling at constant speed with a changing velocity. This happens when the object is changing direction at the same speed.
• Average speed = Distance moved / Time Taken
• Speed and Velocity are both measured in m/s
• Acceleration is how quickly the velocity is changing. This could be change in direction or change in speed or both.
• Unit of acceleration is m/s^2.
• There are TWO formulas for acceleration:

  1. Acceleration = Change in Velocity / Time taken
  2. v^2 = u^2 + 2as
• The first equation for acceleration can be written like:

  (v - u) / t

  "V" is the final velocity and "U" is the initial
• This is the graph of Distance - time.

  Flat sections are where it stops.

  Curves represent acceleration.

  Curve getting steeper means it is speeding up which we call 'increasing gradient.'

  Levelling off curve mean it is slowing down which we call 'decreasing gradient.'

  A) Stopped

  B) Accelerating

  C) Steady speed

  D) Decelerating

  
• Steeper the graph meaning it is increasing in speed.
• This is a steep graph.

  
• This is a velocity - time graph. It shows how an object's velocity changes.

  Gradient = acceleration.

  Flat sections represent steady speed.

  Steeper the graph, greater the acceleration OR deceleration.

  Uphill sections (/) acceleration

  Downhill sections are deceleration.

  Area under any part of the graph is equal to the distance travelled in that time interval.

  Curve means changing acceleration.

  
• Distance - time graph describes the motion of an object.
• specific heat capacity formula: specific heat capacity = mass x specific heat capacity x change in temperature
• Stopping distance:
• Thinking distance: The distance a driver has to travel before they can react to a hazard
• braking distance: distance travelled from the time the brakes are applied to the time the vehicle stops