CK-12-Physics - Intermediate

2.5. The Kinematic Equations http://www.ck12.org

Kinematic Equations

1.vavg=∆∆xt, always true

2.aavg=∆∆vt, always true

3.vf=at+vi, constant acceleration only

4.vavg=(vf+ 2 vi), constant acceleration only

5.x=^12 at^2 +vit+xi, constant acceleration only

6.vf^2 =vi^2 + 2 a∆x, constant acceleration only

The link below shows an example using the kinematic equations for horizontal motion under acceleration.

http://demonstrations.wolfram.com/BrakingACar/

• Displacement is the difference between the ending position and starting position of motion. It is a vector
  quantity.


• Velocity is the rate of change of position. It is vector quantity.


• Average speed can be computed finding the total distance divided by the total time or by a weighted average.


• The slope of a line in the position-time plane represents velocity.


• The area in the acceleration-time plane represents a change in velocity.


• Area in the velocity-time plane represents a change in position (displacement).


• The slope of a line in the velocity-time plane represents acceleration.


• The gravitational acceleration near the surface of the earth is very close to 9. 8 m/s^2.


• The kinematic equations of motion in one dimension are:

1.vavg=∆∆xt, always true

2.aavg=∆∆vt, always true

3.vf=at+vi, constant acceleration only

4.vavg=(vf+ 2 vi), constant acceleration only

5.x=^12 at^2 +vit+xi, constant acceleration only

6.vf^2 =vi^2 + 2 a∆x, constant acceleration only