AP Physics 1: 4 Kinematic Equations to Know Inside and Out
In AP Physics 1, the four kinematic equations are fundamental tools for analyzing motion under constant acceleration. With these formulas, you can connect displacement, velocity, acceleration, and time to solve a wide range of problems accurately.
Here’s what you’ll get in this post:
Clear breakdown of each equation and when to use it
A handy comparison table for quick reference
Pro tips to avoid common mistakes
How targeted AP Physics 1 tutoring can help you master the material
The Four Kinematic Equations—Explained
Δx = v₀ t + ½ a t²
Calculates displacement (Δx) when you know initial velocity, acceleration, and time.v = v₀ + a t
Solves for final velocity when initial velocity, acceleration, and time are known.v² = v₀² + 2 a Δx
Connects velocities and displacement—great when time isn’t given.Δx = ½ (v + v₀) t
Calculates displacement using average velocity and time; especially handy when acceleration is constant.
Quick Reference Table
| Equation | Formula | When to Use |
|---|---|---|
| Displacement & Time | Δx = v₀ t + ½ a t² | Use when initial velocity, acceleration, and time are known and you want displacement. |
| Final Velocity | v = v₀ + a t | When you know initial velocity, acceleration, and time; need final velocity. |
| No Time Involved | v² = v₀² + 2 a Δx | Best when time is not given, but you know velocities and displacement. |
| Average Velocity | Δx = ½ (v + v₀) t | Use if acceleration is constant and you know average velocity and time. |
Pro Tips for Students
Choose your equation based on what variables are given. If time isn't given, avoid equations involving 't'.
Double-check units (e.g. meters vs kilometers, seconds vs hours).
Sketch the scenario to visualize initial/final positions and velocities.
Plug and chug: write down known values before substituting to avoid mix-ups.
How AP Physics 1 Tutoring Can Help
Learning the equations is one thing—knowing how and when to apply them is another. That’s where a personalized tutor comes in:
Identify where you're stuck: equation selection, algebra, unit conversion, or concept gaps
Walk through tailored practice problems
Help build problem-solving strategies and confidence
Stemly’s AP Physics 1 tutoring offers one-on-one sessions that match your learning style, helping you internalize the “why” and “how,” not just the formula.
FAQ
Q: How many kinematic equations are there in AP Physics 1?
A: Four key equations relate displacement, velocity, acceleration, and time under constant acceleration.
Q: Which equation doesn’t use time?
A: The third equation — v² = v₀² + 2aΔx — is used when time isn’t given.
Q: When should you use Δx = ½ (v + v₀) t?
A: When acceleration is constant and you know average velocity and time.