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A child on a bike traveled 20 m east, and then 30 m north. What was the displacement of the child?

User Akshansha Singhal
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1 Answer

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6 votes

Hint: By drawing a rough figure we can find the direction of displacement of the person, magnitude can be found by using the Pythagoras theorem.

Step-by-step explanation:

Let AB be the displacement of the person towards the North, BC be the displacement towards the south and CE be the displacement in the South-West direction. We have to find the displacement of the person from the origin, EA

Consider the right triangle ECD, by Pythagoras' theorem

ED² +CD² =EC² → (i)

From fig, CD = AB = 30m

EC = 30√2m

ED = EA + AD

AD = BC = 20m

∴ ED = EA + 20m

(i) → (EA + 20)² + (30)² = (30√2)²

(EA + 20)² + 900 + 1800

EA + 20 = 30

EA=10m

The displacement of the person from the origin will be 10m along West.

User Tiago Geanezini
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