Q-39. Leela starts from a point and walks 1 km east and then turns left and walks 2 km and again turns right and walks 2 km again. She starts towards a point 2 km towards her right, from where again she walks 1 km left. How far is she from the starting point? (a)3km(b)4 km (c) 5km (d) 2 km a in
Q-39. Leela starts from a point and walks 1 km east and then turns left and walks 2 km and again turns right and walks 2 km again. She starts towards a point 2 km towards her right, from where again she walks 1 km left. How far is she from the starting point? (a)3km(b)4 km (c) 5km (d) 2 km a in
Answer
To determine how far Leela is from the starting point, let's break down her journey step by step and visualize her movements on a coordinate plane.
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Starting Point:
- Let's assume Leela starts at the origin .
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First Movement:
- She walks 1 km east.
- New position: .
-
Second Movement:
- She turns left (north) and walks 2 km.
- New position: .
-
Third Movement:
- She turns right (east) and walks 2 km.
- New position: .
-
Fourth Movement:
- She starts towards a point 2 km to her right (east).
- New position: .
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Fifth Movement:
- She walks 1 km left (west).
- New position: .
Now, we need to find the distance from her final position to the starting point .
The distance between two points and is given by the distance formula:
Substituting the coordinates of the starting and final points:
However, the options provided are in whole numbers. Let's approximate :
Since the options are whole numbers, we need to re-evaluate the problem to ensure there are no calculation errors. Let's recheck the movements:
- Starting at .
- Moves to .
- Moves to .
- Moves to .
- Moves to .
- Moves to .
The final position is indeed , and the distance from to is:
Given the options, the closest whole number is 4 km.
Thus, the correct answer is:
Key Concept
The problem involves understanding the concepts of:
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Coordinate Geometry: Visualizing movements in a coordinate system (starting point as the origin).
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Vector Addition: Breaking down Leela's path into segments to determine her final position.
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Distance Calculation: Using the distance formula or geometric principles to find the straight-line distance between points.
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Directions and Angles: Understanding left and right turns to accurately plot movements on a map.
By following these principles, you can determine how far Leela is from the starting point after completing her route.