9. A girl moves along a circular path of radius 14m. What is her distance and displacement when she completes: (a) Half round (b)Two rounds

Asked by tognosigno | 2nd May, 2020, 11:05: AM

Expert Answer:

Radius of circular path, r = 14 m 
 
a) Half round 
 
Distance when girl completes half round
 
We know,
circumference of circle = 2∏r 
Thus circumference of semicircle (half circle) = ∏r 
Hence, 
 
D i s tan c e space w h e n space g i r l space c o m p l e t e s space h a l f space r o u n d space equals space 22 over 7 cross times 14 space equals space 44 space m space

D i s p l a c e m e n t space equals space d i a m e t e r space o f space t h e space c i r c l e space equals space 2 space cross times r equals 2 cross times 14 space equals space 28 space m space 
 
b) Two rounds
 
W h e n space g i r l space c o m p l e t e s space t w o space c i r c l e s space

D i s tan c e space t r a v e l l e d space b y space h e r space o n space c o m p l e t i n g space t w o space r o u n d s space o f space c i r c u l a r space p a t h space equals space 2 space open parentheses 2 pi r close parentheses space equals space 2 space cross times open parentheses 2 cross times 22 over 7 cross times 14 close parentheses space equals space 176 space m space


D i s p l a c e m e n t space w h e n space g i r l space c o m p l e t e s space t w o space r o u n d s space o f space c i r c u l a r space t r a c k space equals space 0 space
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Answered by Shiwani Sawant | 2nd May, 2020, 01:20: PM