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?

Answer :

We have

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 2^{nd} floor of the basement and it is given that, distance between floors is 5 m.

So, distance between ground and 1^{st} floor of basement = 5 m

And distance between 1^{st} floor and 2^{nd} floor of basement = 5 m

⇒ Distance between ground and 2^{nd} floor of basement = 5 + 5

⇒ Distance between ground and 2^{nd} floor of basement = 10 m

Total distance between man and 2^{nd} floor of the basement is given by,

Total distance = Distance between man and ground + Distance between ground and 2^{nd} 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.

Since,

⇒

⇒

⇒ Time = 60 s

Thus, it takes 60 seconds or 1 minute to reach at 2^{nd} floor of the basement.

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