# P2 Chapter 1 Revision

?

## 1.1 Distance - time Graphs

• The slope on a distance time graph represents speed.
• The steeper the line on a distance - time graph, the greater the speed
• speed (m/s) = distance travelled (m)/ time taken (s)

1 of 4

## 1.2 Velocity and Acceleration

• Velocity is speed in a given direction.
• Velocity is sometimes a more useful measure of motion, because it describes both speed and direction.
• The acceleration of an object is its change of velocity per second.
• Acceleration is measured in metres pre second squared.
• Acceleration = change in velocity (m/s)/ time taken for change (s)
• A body travelling at a steady speed is accelerating if its direction is changing.
• We use the term negative deceleration in any situation where an object slows down.
2 of 4

## 1.3 More about Velocity-time Graphs

• The slope of the line on a velocity-time graoh represents acceleration.
• Braking reduces the velocity of a vehicle.
• The area under any section of the graph is equal to the displacement (distance) travelled in that time interval.
• The area under the line on a velocity-time graph represents distance travelled.
3 of 4

## 1.4 Using Graphs

• For an object moving at a constant speed, the distance-time graph is a straight line.
• For a moving object with a changing speed, the distance-time graph is not a straight line.
• The slope on a velocity-time graph represents acceleration.
• To find the distance travelled from the graph, remember the area under a velocity-time graph represents the distance travelled.
4 of 4