The moment you’re given the task of solving kinematics equations, you may feel overwhelmed. While these equations can be frustrating at times, they are not impossible to solve. Here are 6 tips to help you understand kinematics equations.
Know The Meaning of Kinematic Equations
Before you can begin to solve a kinematic equation, you must first understand its purpose. If you don’t, the solution will be lost in the translation. A good way to do this is to learn about coordinate systems before diving into these equations. The folks at PASCO explain that kinematic equations are used when analyzing motion. They help to determine the displacement, direction of an object’s velocity, and speed if the initial position and velocity of an object are known. This knowledge is helpful whether you’re studying or just enjoying a hobby that involves physics.
Choose Solvable Variables
The variables most commonly found in kinematic equations are time (“t”), displacement (“s”), and acceleration (“a”). Learning these variables gives you a head start in solving an equation because they are the only variables you need to know.
Be sure to train yourself on choosing which variable to use and when to use it. It will make these equations much less stressful and easier to understand. A good rule of thumb is that if there is movement, then there must be acceleration otherwise, there is no acceleration needed so you can choose time or displacement.
Know What Each Term Means
You need to know what each part in the equation represents before you solve an equation. If you understand what each term means, solving the kinematics equation will be a much easier task to complete. Here are the terms and what they mean:
Distance – Distance is most commonly known as the length of a straight line from point A to point B.
Initial Velocity – The initial velocity is how fast an object starts at, and will always be represented by a lowercase v with a subscript 0 (v0).
Final Velocity – This is how fast an object is traveling at the end of its motion. This term is represented by a lowercase v with a subscript f (vf).
Time – The time interval is how long an object has been in motion for and will always be represented by a lowercase t with a subscript i (ti), or a lower case t with a subscript f (tf).
Acceleration – This is how an object’s velocity changes over time and will be represented by a lowercase letter with a subscript i or f (a or af).
Displacement – The displacement of an object would be the total amount of movement from its initial position to a final position, and will always be represented by a lowercase letter with a subscript i (s or si).
Use the Pythagorean Theorem
Don’t forget that the Pythagorean Theorem is your friend, especially when you’re solving kinematic equations. It can be used to solve for any unknown variable in a kinematic equation because it’s an easy way to show motion. Another good thing about using the Pythagorean Theorem is that it will allow you to solve for your unknown variable in a systematic way.
This equation allows you to find distance and final velocity if initial velocity and initial position are known:
vf = vi + at
Use Units of Measure
No matter what units you use for your measurements, make sure that they are all in the same units. For example, if one distance is given in meters and another is given in feet, then a length cannot be determined. If a final velocity is measured in miles per hour and an initial velocity is measured by kilometers per minute, then a value cannot be determined. Also, after solving for your unknown variable, make sure to check that your answer makes sense in the context of where it’s found. For example, if an object starts at 10 meters and ends at 20 meters, then its final velocity would be (20-10 = 10 / 2 * 5 + 10) or 30 m/s.
Be Sure to Show Your Work
“Worked Examples” and “Solutions” will be the best way for you to understand what you’re doing wrong and how to correct it. While they may be the most time-consuming, in the end, they will save you much more time rather than going through a number of incorrect work products.
So now you have six easy ways to help you understand kinematic equations. Follow these tips, practice them daily with whatever kinematic equations are given to you, and soon enough you’ll be solving your own equations without any help at all! Remember, if you want to improve your grades or understanding, then show your work. This will show what you did right and more importantly, what you did wrong.