Скачать или смотреть Distance and Displacement | Topic 2 - part 1 | Class 9th | MOTION | chapter 8 science

Distance and Displacement | Topic 2 - part 1 | Class 9th | MOTION | chapter 8 science #physicsncert

📘 Class 9 – Science (Physics)

✨ Topic: Distance and Displacement


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🔹 1. Distance

Definition: Distance is the total path length travelled by an object, no matter the direction.

Scalar Quantity: It only has magnitude (no direction).

Always Positive: Distance is never zero or negative.

SI Unit: Metre (m)


📝 Example:
If a person walks 4 m east and then 3 m west, the total distance travelled is:
4 m + 3 m = 7 m


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🔹 2. Displacement

Definition: Displacement is the shortest distance between the initial and final positions of the object in a specific direction.

Vector Quantity: It has both magnitude and direction.

Can be Positive, Zero, or Negative.

SI Unit: Metre (m)


📝 Example:
If a person walks 4 m east and then 3 m west,
Net movement = 4 m – 3 m = 1 m east
So, Displacement = 1 m east


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🔁 Difference Between Distance and Displacement

Feature Distance Displacement

Type Scalar quantity Vector quantity
Direction No direction Has direction
Value Always positive Can be positive, zero, or negative
Path Actual path taken Shortest path (straight line)
Magnitude greater than or equal to Displacement less than or equal to Distance



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🎯 Important Points

If the object returns to the starting point, displacement = 0, but distance grater than 0

Displacement can never be more than distance.

Both have the same unit: metre (m)



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🧠 Example-Based Question

Q: A car moves 5 km north and then 5 km south. What is the distance and displacement?



✔ Distance = 5 km + 5 km = 10 km
✔ Displacement = Final – Initial = 0 km (back to starting point)


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