Acceleration — Science definition
Defined in 2 courses:
- How quickly velocity changes over time, found by dividing the change in velocity by the time it took. (Physical Science: Matter, Forces & Energy)
- The rate at which velocity changes: a = (v − v₀) ÷ t. A vector, measured in m/s². (Physics & Environmental Science)
Where it is taught
- Speed, Velocity & Acceleration — Motion, Physical Science: Matter, Forces & Energy, Grade 8
- Velocity & Acceleration — Motion & Kinematics, Physics & Environmental Science, Grade 12
In use
Acceleration measures how quickly velocity is changing — how fast you're speeding up, slowing down, or turning.
Speed, Velocity & Acceleration
Acceleration is the next step up: the rate at which velocity changes, a = (v − v₀) ÷ t, measured in meters per second per second, or m/s².
Velocity & Acceleration
Questions using acceleration
Problem 1
Answer and explanation
2 m/s²
Acceleration = (8 − 2) ÷ 3 = 6 ÷ 3 = 2 m/s².
Problem 2
Answer and explanation
-5 m/s²
Acceleration = (10 − 30) ÷ 4 = −20 ÷ 4 = −5 m/s². The negative sign shows it's slowing down.
Problem 3
Hints
State what the supplied observations or conditions establish, and separate that from any assumption.
Answer and explanation
(10−2)/4=2 m/s² east, assuming east is positive.
Problem 4
Answer and explanation
(−8−(−2))/3 = −2 m/s². It speeds up toward the left because speed rises from 2 to 8 m/s.
Subtract signed velocities before dividing.
Compare velocity direction with acceleration direction.
Response criteria
- Calculate −2 m/s².
- Explain leftward motion.
- Reject negative-always-slows.
Taught alongside
- speed
- velocity
- model
- evidence
- system boundary
- assumption
- average velocity
- instantaneous velocity
- average speed
- free fall
- g