5 Things You Should Know About Kinematic Equations

5 Things You Should Know About Kinematic Equations

Kinematic equations provide information about the motion of an object under constant acceleration. It is not technically possible to measure acceleration, however, so kinematic equations instead measure variables of time, position, and velocity. They are also used to solve many problems relating to constant acceleration.

If you aren’t a physician or mathematician, it’s likely that the concept of kinematic equations will be quite confusing to you. That’s understandable. If that is the case, then we’ve got you covered. This article will present and explain five important things that we think you should know about kinematic equations:

What is Kinematics?

Before we can begin to explain the kinematic equations, we must first cover what kinematics is. Kinematics is the study of motion, without studying the forces that cause that motion. Kinematics focuses on velocity, position, and acceleration, but not forces. A force, for example, could be a person’s arm, when throwing a ball. There are five quantities in kinematics, which are displacement, initial velocity, final velocity, acceleration, and time.

The final velocity is how fast an object is moving when time is over. Initial velocity is how fast an object is moving when time begins. Displacement is how much the object’s position changed during that time. And, acceleration is the rate at which the object’s velocity changed during time. Time, as one might expect, is the time that the object’s acceleration is being calculated. Kinematic problems are solved using graphs and equations.

Kinematic Equations

The first thing that you need to know about kinematic formulas is what they are made up of. According to the kinematic experts from Pasco, kinematic equations require knowledge of derivatives, rate of change, and integrals, so that an object’s acceleration can be measured. These things are the five kinematic variables, which are:

  • t time interval
  • v0 initial velocity
  • v final velocity
  • a constant acceleration
  • Δx displacement

Kinematic equations provide an effective method of predicting information about an object’s motion, as long as other information is known. For example, if one knows just three of the aforementioned kinematic variables for an object under constant acceleration, then a kinematic formula can be used to determine the unknown variables, therefore calculating an object’s speed. Kinematic formulas are only accurate if an object’s acceleration is constant during the time interval that the object is studied in. The equations will not work if they are used when an object’s acceleration is changing (slowing down). Additionally, all of the kinematic formulas assume that an object is travelling in a single direction.

When to Use a Kinematic Equation?

As already mentioned, kinematics is the study of object motion, without studying the forces that actually cause motion. Kinematic equations are very simple ways of understanding an object’s motion. Three of them assume constant acceleration, while two assume zero acceleration and constant velocity. Kinematic equations can solve object motion problems. For example, they can be used to determine how far an object flies, as long as the object is under constant acceleration. Another example of when a kinematic equation can be used is when a car is being driven at a constant velocity because it has zero acceleration, the equation that has no acceleration terms can be used.

How Do You Select a Kinematic Equation?

When you are selecting a kinematic equation, naturally you select the one that includes both the unknown variable and the three kinematic variables that are already known. By doing so, the unknown variable that you are hoping to calculate or determine can be discovered.

In order to choose the right kinematic formula, you need to determine which variable you have not been given. In the problem that you have been assigned, identify which variable is missing.

Nearly all problems posed that require the use of kinematic equations will require you to solve an unknown, which could be initial displacement, final displacement, change in displacement, acceleration, time, initial velocity, or final velocity. Put simply, a kinematic equation is chosen according to both what is known and what is unknown. Some questions require more than one equation to be used sequentially in order to find the value of an unknown.

Studying Kinematics

Kinematics is an incredibly complex subject. If you are interested in learning more about it, then a course is definitely worth attending. Alternatively, you can study online learning resources, watch videos, and read articles like this. Kinematics does require a lot of practise to master, though through dedication and commitment, it can be mastered.

Kinematics is a very important branch of physics. This article provides a very basic glimpse into it, by telling you about five things that you need to know. As already mentioned, it is definitely worth enrolling in a course if the subject interests you.

About the author


Steven Ly

Steven Ly is the Startup Program and Events Manager at TheNextHint Inc. She recruits rockstar startups for all TC events including Disrupt, meetups, Sessions, and more both domestically and internationally. Previously, she helped produce Dreamforce with Salesforce and Next '17 with Google. Prior to that, she was on the advertising teams at both Facebook and AdRoll, helping support advertisers in North America and helped grow those brands globally. Outside of work, Priya enjoys Flywheel, tacos, the 49ers, and adventuring around the globe.

Add Comment

Click here to post a comment

Your email address will not be published.

Subscribe us

Please wait...
Want to be notified when our article is published? Enter your email address and name below to be the first to know.
error: Content is protected !!