P2 U2 Motion

P2 U2 Motion

1. Distance-time graphs

   • The gradient of the line on a distance-time graph represents an object's speed.
   • The steeper the line on a distance-time graph, the greater the speed it represents.
   • We can use graphs to help us describe the motion of an object.
   • A distance-time graph shows the difference of an object from a starting point (y-axis) against time taken (x-axis)
   • The speed of an object is the distance travelled each second
   • The gradient of the line on a distance-time graph represents speed. The steeper the gradient, the greater the speed.
   • If an object is stationary, the line on a distance-time graph is horizontal.
   • If an object is moving at a constant speed, the line on a distance-time graph is a straight line that slopes up.

2. Velocity and acceleration

   • The velocity of an object is its speed in a given direction.
   • If the object changes direction it changes velocity, even if its speed stays the same.
   • If the velocity of an object changes, we say that ut accelerates.
   • If the value calcualted for acceleration is negative, the body is decelerating (slowing down). A deceleration is the same as a negative acceleration.

3. Velocity-time graphs

4. Using graphs