Question

1. An object is moving in a circular path of Radius (R) calculate the distance and displacement
(i) When it completes half circle
(ii) When it completes full circle

​

Answer 1

The radius of the circle= r

(i) When it completes half circle:-

(Refer to Image 1)

Distance=

2

circumference

=

2

2πr

Distance= πr

Displacement= r+r=2r

(ii) When it completes 3/4

th

of the circle:-

The distance covered=

4

3

(circumference)

⇒

4

3

(2πr)=

2

3

πr

The displacement= AB (Refer to Image 2)

By using pythagoras theorem

AB

2

=r

2

+r

2

⇒AB

2

=2r

2

⇒AB=

2

r

Displacement=

2

r

Distance=

2

3

πr

Answer 2

Explanation:

Half circle

Distance =22/7 X R

Displacemant = R+R=2R

Full circle

Distance=2 X 22/7 X R

Displacement = 0

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