Velocity time graph analysis, acceleration calc
🏎 1. Velocity-Time (v-t) Graphs
🔹 Axes
Y-axis → Velocity (m/s)
X-axis → Time (s)
🔹 Key Features
Feature | Meaning |
|---|---|
Horizontal line | Constant velocity (acceleration = 0) |
Upward sloping line | Acceleration (speed increasing) |
Downward sloping line | Deceleration (speed decreasing) |
Area under graph | Distance travelled |
🔹 Calculating Distance
Area under the graph = distance
Formulas:
Rectangle → width × height
Triangle → ½ × base × height
Example:
Triangle area: ½ × 4 s × 10 m/s = 20 m
Rectangle area: 5 s × 8 m/s = 40 m
Total distance = 60 m
⚡ 2. Acceleration Calculations
🔹 Definition
Acceleration (a) = rate of change of velocity
a=change in velocitytimea = \frac{\text{change in velocity}}{\text{time}}a=timechange in velocity
🔹 Formula
a=v−uta = \frac{v - u}{t}a=tv−u
vvv = final velocity (m/s)
uuu = initial velocity (m/s)
ttt = time (s)
🔹 Example Calculation
Initial velocity u=2 m/su = 2\,\text{m/s}u=2m/s
Final velocity v=10 m/sv = 10\,\text{m/s}v=10m/s
Time t=4 st = 4\,\text{s}t=4s
a=10−24=84=2 m/s²a = \frac{10 - 2}{4} = \frac{8}{4} = 2\,\text{m/s²}a=410−2=48=2m/s²
🔹 Key Tips
Positive slope → positive acceleration
Negative slope → deceleration (negative acceleration)
Area under graph → distance
🔗 Big Links
V-t graphs → visual representation of motion
Acceleration = slope of the graph
Distance = area under the graph
⭐ Exam Tips
Always label velocity and time axes
Identify slope → acceleration
Use correct units → m/s² for acceleration, m for distance
Practice both slope and area methods