In short
Acceleration is change in velocity over time. Use s = ut + ½at² for distance when it starts from rest or at speed u.
Two ideas
Velocity is how fast you are going and in which direction. Acceleration is how quickly your velocity changes.
a = Δv / Δt
Worked example
A car starts from rest and reaches 20 m/s in 5 s. Find its acceleration and the distance covered.
- Acceleration: a = (20 − 0) / 5 = 4 m/s².
- Distance: s = ut + ½at² = 0 + ½ × 4 × 5² = 0 + 2 × 25 = 50 m.
The common mistake
Try it: a car starts from rest and reaches 12 m/s in 6 s. Find a and the distance. Answer: a = 2 m/s², s = ½ × 2 × 6² = 36 m.
AI explanations can contain mistakes. Check important answers with your teacher.
AI explanations can contain mistakes. Check important answers with your teacher.