Motion

• The distance-time garph for any object that is:

  • Stationary, is a horizontal line
  • Moving at a constant speed, is a straight line taht slopes upwards.
• The gradient of a distance-time graph for an object represents the object's speed.
• Velocity is speed in a given direction.
• Deceleration is the change of velocity per seconf when an object slows down.
• A motion sensor linked to a computer can be used to measure velocity changes.
• The gradient of the line on a velocity-time graph represents acceleration.
• If a velocity-time graph is a horizontal line, the acceleration is zero.
• A positive gradient on a velocity-time graph represents positive acceleration, a negative gradient represents deceleration.
• The area under the line on a velocity-time graph represents distance travelled.
• The speed of an object moving at constant speed is given by the gradient of the line on its velocity-time graph.
• The acceleration of an object is given by the gradient of the line on its velocity-time graph.
• The speed, at any instant of time, of an object moving at changing speed is given by the gradient of the tangent to the line on its distance-time graph.