In this topic of IBDP Physics, we will learn about acceleration.

Acceleration

In IBDP Physics, you should be able to calculate the *acceleration* of an object from its change in velocity and the time taken.

The Equation

When an object moves in a straight line with a constant acceleration, you can calculate its acceleration if you know how much its velocity changes and how long this takes. This equation shows the relationship between acceleration, change in velocity and time taken:

- For example, a car accelerates in 5s from 25m/s to 35m/s.
- Its velocity changes by 35 - 25 = 10m/s.
- So its acceleration is 10 Ă· 5 = 2m/s
^{2}.

Distance-time graphs

In IBDP Physics, the gradient of a line on a distance-time graph represents the speed of the object. Study this distance-time graph.

The area

The area under the line in a velocity-time graph represents the distance travelled. To find the distance travelled in the graph above, we need to find the area of the light-blue triangle and the dark-blue rectangle.

- Area of light-blue triangle
- The width of the triangle is 4 seconds and the height is 8 metres per second. To find the area, you use the equation:
- area of triangle =
^{1}⁄_{2}× base × height - so the area of the light-blue triangle is
^{1}⁄_{2}× 8 × 4 = 16m.

- Area of dark-blue rectangle
- The width of the rectangle is 6 seconds and the height is 8 metres per second. So the area is 8 × 6 = 48m.

- Area under the whole graph
- The area of the light-blue triangle plus the area of the dark-blue rectangle is:
- 16 + 48 = 64m.
- This is the total area under the distance-time graph. This area represents the distance covered.

Summary

In IBDP Physics,

- the gradient of a velocity-time graph represents the acceleration
- the area under a velocity-time graph represents the distance covered

This is the end of this topic.