Physics Formulas Kinematics With Appropriate Graphs
Kinematics in physics is about the motion of a body or an obeject. And the terms associated with kinematics are displacement, speed, velocity, and acceleration. These are the variables physicists play around in this topic.
Kinematics formulas
The starting point is from the definition of acceleration which is the rate of change of velocity. This is like a car travelling at a certain speed then the driver decided to move faster or slower by pressing the accelerator. The speedometer in the car will change and at that instance the car has either accelerate or decelerate.
Acceleration = change of velocity / time = (v – u) / t
u is the initial velocity, v is the final velocity, t is the time taken, and a is the acceleration
cross multiply,
Make v the subject of the equation
The first formula above is the Newton’s first equation of motion
The next step,
From average velocity,
Average velocity = s / t
Average velocity = (v +u)/2
Equate the two equations together, you get
s / t = (v +u)/2
Cross multiply and rearrange
s = [(v + u)t]/2
substitute v = u + at into s = [(v + u)t]/2
you have
This is the Newton’s second equation of motion
Recommended: Short notes on motion
Final step:
Make t the subject of the Newton’s first equation of motion
t = (v – u) / a
substitute t = (v – u) / a into Newton’s second equation of motion
Cross multiply,
This is the Newton’s third equation of motion
The next thing is to look at Kinematics graphs
