Acceleration and V-T graphs

• Average speed = total distance travelled / total time taken
• What is the equation for speed?

  Speed = distance / time
• What does a horizontal line in a distance- time graph represent?

  • It means the object isn’t moving. Distance stays the same as time passes, so the object's position is constant/ zero speed
• What does a positive gradient line mean in a distance- time graph represent?

  • A positive gradient means the object's moving away from its starting point. The steeper the gradient, the faster it's moving/ the speed is constant.
• What does a negative gradient line mean in a distance- time graph?

  It means the object is moving back towards its starting point. Essentially, the distance from the starting point decreases over time
• • Acceleration is the increase in speed
  • Deceleration is the decrease in speed.
• The equation for Acceleration and Deceleration is the same but the speed isn’t the same. This equation is used for both because to calculate it you need change in velocity, but it does not specify whether it increases or decreases velocity
• 
  

  Word equation for Acceleration and Deceleration:

  Change in velocity

  Acceleration = —————————————-

  Time
• The symbol equation ( must remember)

  B - Acceleration

  C - Change in velocity

  D - Time

  
• • Acceleration is measured in metres per second squared (m/s2).
  • Velocity is measured in metres per second ( m/s)
  • Time is measured in seconds (s)
• Acceleration is the rate of change of velocity at any given instant, while average acceleration is the overall change in velocity divided by the total time taken.
• Average acceleration can be calculated using the formula: Average acceleration = Total change in velocity / Total time taken