58. A boy walks from his classroom to the bookshop along a straight corridor towards North. He covers a
distance of 20 m in 25 seconds to reach the bookshop. After buying a book, he travels the same distance in
the same time to reach back in the classroom. Find (a) average speed, and (b) average velocity, of the boy.
please help me to answer this question
Share
GiveN :
To FinD :
Solution :
We are given that a boy starts walking from his classroom to bookshop shop which is 20 m in 25 seconds.
⇒Total distance = 20 + 20 = 40 m
⇒Total time taken = 25 + 25 = 50 seconds
Because boy moves from classroom to bookshop and also returns with same path in same time.
⇒Speed = Distance/Time
⇒Speed = 40/50
⇒Speed = 4/5
⇒Speed = 0.8
∴ Speed of boy is 0.8 m/s
___________________________
As the boy walk to bookshop and returns to classroom. So, his displacement will be 0 m
⇒Velocity = Displacement/Time
⇒Velocity = 0/25
⇒Velocity = 0
∴ Velocity of boy is 0 m/s
Verified answer
[tex]\large{\red{\bold{\underline{\underline{Answer}}}}}[/tex]
[tex] \purple{\sf{\mapsto Average\:speed=0.8\:m/s}}\\ \\\purple{\sf{\mapsto Average\: velocity=0}}[/tex]
[tex]\bold{\green{\underline{Given}}} \\ \\ \sf{\rightsquigarrow Distance\: traveled = 20\: m} \\ \\ \sf{\rightsquigarrow Time \: taken = 25\: s } \\ \\ \bold{\blue{\underline{To \: Find}}} \\ \\ \sf{\rightsquigarrow Average \: speed =\:?}\\ \\ \sf{\rightsquigarrow Average \: velocity =\:?}[/tex]
[tex]\\[/tex]
❏ According To Given Question
[tex] \\ \sf{a)} \: Average \: speed = \frac{Total \:distance}{Total \: time} \\ \\ \sf{: \implies Average \: speed = \frac{2(20)}{2(25)} } \\ \\ \sf{ : \implies Average \: speed = \frac{40}{50} } \\ \\ \sf{ \purple{ : \implies \underline{ \boxed{ \sf{ Average \: speed =0.8 \: m/s}}}}} \\ \\ \sf{b) \: Average \: velocity = \frac{Total \: displacement}{Total \: time} } \\ \\ \sf{ : \implies Average \: velocity = \frac{0}{2(25)} } \\ \\ \sf{ : \implies Average \: velocity = \frac{0}{50} } \\ \\ \sf{ \purple{ : \implies \underline{ \boxed{ \sf{Average \: velocity =0 }}}}}[/tex]