Q. 1344.3( 7 Votes )
A multistorey building has 25 floors above the ground level each of height 5m. It also has 3 floors in the basement each of height 5m. A lift in building moves at a rate of 1m/s. If a man starts from 50m above the ground, how long will it take him to reach at 2nd floor of basement?
Since, it is given that the man starts from 50 m from the ground.
⇒ Distance of the man from the ground = 50 m
There are about 3 floors in the basement.
The man has to reach the 2nd floor of the basement and it is given that, distance between floors is 5 m.
So, distance between ground and 1st floor of basement = 5 m
And distance between 1st floor and 2nd floor of basement = 5 m
⇒ Distance between ground and 2nd floor of basement = 5 + 5
⇒ Distance between ground and 2nd floor of basement = 10 m
Total distance between man and 2nd floor of the basement is given by,
Total distance = Distance between man and ground + Distance between ground and 2nd floor basement
⇒ Total distance = 50 + 10
⇒ Total distance = 60 m
But, the speed of lift = 1 m/s
We need to find the time taken by the lift to reach 60 m at speed, 1 m/s.
⇒ Time = 60 s
Thus, it takes 60 seconds or 1 minute to reach at 2nd floor of the basement.
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