= 59.9 km h-1Example 10. A man walks at 1 m/s for 60 minHe takes rest

1.	= 59.9 km h-1Example 10. A man walks at 1 m/s for 60 minHe takes rest for 20 minutes and then walspeed of 1 m/s for 60 minutes. Find its aveed.
Answer» Given--- Distance covered by the man in 1 second. = 1 m.∴ Distance covered by the man in 60 min.= 1× 60× 60 = 3600 m.Now,Distance covered by the man is the 20 min. = 0 m.[Since boy is taking the rest] Distance covered by the man in last 60 min. = 1 m× 60× 60= 3600 m. ∴ Total Distance Covered by the man = 3600 + 0 + 3600 = 7200 m. Total Time taken by the man = 60 min. + 20 min. + 60 min.= 140 min.= 140× 60 seconds.= 8400 seconds. Now,∵ Average Speed = Total Distance/Total Time = 7200/8400 = 72/84 = 6/7 m/s. ∴ Average Speed of the man during the entire Journey is 6/7 m/s.

= 59.9 km h-1Example 10. A man walks at 1 m/s for 60 minHe takes rest for 20 minutes and then walspeed of 1 m/s for 60 minutes. Find its aveed.

Answer»

Given---

Distance covered by the man in 1 second. = 1 m.∴ Distance covered by the man in 60 min.= 1× 60× 60 = 3600 m.Now,Distance covered by the man is the 20 min. = 0 m.[Since boy is taking the rest]

Distance covered by the man in last 60 min. = 1 m× 60× 60= 3600 m.

∴ Total Distance Covered by the man = 3600 + 0 + 3600 = 7200 m.

Total Time taken by the man = 60 min. + 20 min. + 60 min.= 140 min.= 140× 60 seconds.= 8400 seconds.

Now,∵ Average Speed = Total Distance/Total Time = 7200/8400 = 72/84 = 6/7 m/s.

∴ Average Speed of the man during the entire Journey is 6/7 m/s.

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