Acceleration is one of the most important ideas in IB Physics. It appears in motion graphs, Newton’s Laws, circular motion, energy problems, and nearly every unit involving forces or kinematics. Understanding how to calculate acceleration from velocity and time gives you a strong foundation for solving real exam questions. High-scoring students tend to master this relationship early because it simplifies many multi-step problems—a habit highlighted in The Quest for a 7 in IB Physics (https://www.revisiondojo.com/blog/the-quest-for-a-7-in-ib-physics) .
The Core Formula for Acceleration
Acceleration is defined as the rate of change of velocity.
The basic formula you will use in IB Physics is:
a = Δv / Δt
Where:
- a = acceleration (m/s²)
- Δv = change in velocity (final – initial)
- Δt = change in time
This formula appears in the IB Physics Data Booklet and is one of the most frequently used equations in the entire course. If you ever struggle to locate formulas efficiently, the IB Physics Formula Sheet & Data Booklet Guide (https://www.revisiondojo.com/blog/ib-physics-formula-sheet-data-booklet-ultimate-2025-guide-must-know-tips) explains where every motion equation can be found.
What Acceleration Really Tells You
Acceleration measures how quickly velocity changes, not just speed. This includes changes in:
- Magnitude (speeding up or slowing down)
- Direction (turning, circular motion)
So, an object can accelerate even when traveling at a constant speed, as long as the direction changes. This detail often surprises new students, but mastering it leads to major improvements in understanding motion.
This type of conceptual clarity is one of the strategies emphasized in How to Get a 7 in IB Physics (New Syllabus 2025 Onward) (https://www.revisiondojo.com/blog/how-to-get-a-7-in-ib-physics-new-syllabus-2025-onward) , especially when handling high-level motion problems.
Using Velocity–Time Graphs
Velocity–time graphs are a powerful tool for calculating acceleration. On a v–t graph:
- Acceleration is the slope (gradient)
- The steeper the slope, the greater the acceleration
- A negative slope indicates deceleration
Example:
If velocity increases from 2 m/s to 10 m/s over 4 seconds:
- Δv = 10 – 2 = 8 m/s
- Δt = 4 s
- a = 8 / 4 = 2 m/s²
Students who master graph interpretation perform more confidently in Paper 2, especially with multi-mark reasoning questions.
Real-World IB Physics Examples
You will calculate acceleration from velocity and time in:
- Projectile motion
- Car acceleration problems
- Motion down ramps
- Terminal velocity investigations
- Circular motion (centripetal acceleration)
- Newton’s Laws problems
- Momentum changes (impulse)
Acceleration is a recurring theme across the syllabus, which is why strengthening this concept has an outsized effect on your exam consistency. This is reflected in exam trends explained in IB Physics Grade Boundaries Explained (https://www.revisiondojo.com/blog/ib-physics-grade-boundaries-explained-what-you-need-to-know-for-success) .
Acceleration in the IB Physics IA
Many Internal Assessments rely on acceleration because it is measurable, repeatable, and experimentally rich. Common IA designs include:
- Investigating acceleration down an incline
- Using motion sensors to track velocity changes
- Exploring air resistance and terminal velocity
- Studying oscillatory acceleration in springs or pendulums
Acceleration-based projects provide clean data and meaningful analysis opportunities. If you want inspiration for physics experiments involving motion, Top 10 Fresh IB Physics IA Ideas 2025 (https://www.revisiondojo.com/blog/top-10-fresh-ib-physics-ia-ideas-2025-how-revisiondojo-can-supercharge-your-ia) includes several strong candidates.
Common Misconceptions
Students often misunderstand acceleration because they:
- Think acceleration only means speeding up
- Forget that changing direction is acceleration
- Mix up distance and displacement
- Forget to use negative signs correctly
- Confuse average acceleration with instantaneous acceleration
Clearing up these misconceptions early strengthens your understanding of later topics like forces, circular motion, and momentum.
For last-minute revision of motion formulas, many students rely on condensed strategies from How to Cram IB Physics in 1 Week (https://www.revisiondojo.com/blog/how-to-cram-ib-physics-new-syllabus-2025-onward-in-1-week-a-survival-guide) .
FAQ
Can acceleration be negative?
Yes. Negative acceleration means velocity is decreasing or direction is reversed.
Is acceleration always constant in IB questions?
No, but many simplified problems assume constant acceleration to make calculations easier.
Can acceleration occur at constant speed?
Yes—any change in direction counts as acceleration.
RevisionDojo Call to Action
If you want full confidence in mechanics, motion graphs, and the entire IB Physics syllabus, RevisionDojo gives you the structure, clarity, and support you need. From exam prep to IA design, RevisionDojo helps you reach your best performance.
