If an object moves along a straight line, its motion can be represented by a velocity-time (or speed-time) graph. The gradient of the line is equal to the acceleration of the object.
The table shows what each section of the graph represents:
|Section of graph||Gradient||Velocity||Acceleration|
|D (v = 0)||Zero||Stationary (at rest)||Zero|
The area under the graph can be calculated by:
Calculate the total displacement of the object - its motion is represented by the velocity-time graph below.
Here, the displacement can be found by calculating the total area of the shaded sections below the line.
1. Find the area of the triangle:
area of triangle = × base × height
= × 4 × 8 = 16 m2
2. Find the area of the rectangle:
area of rectangle = base × height
= (10 - 4) × 8 = 48 m2
3. Add the areas together to find the total displacement:
(16 + 48) = 64 m