A 20m deep well with diameter 7m is dug and the earth digging is evenly spread out to form a platform 22m by 14m.Find the height of the platform
Answers
Given:
Depth (h) of well = 20m.
Radius (r) of circular end of well = 7/2 m.
Find:
The height of platform is
Solution:
Let height of the platform = h
Area of platform = length × breadth
=> 22 × 14
=> 308m²
Volume of soil dug from the well will be equal to the volume of soil scattered on the platform.
Volume of soil from well = Volume of soil used to makes sure platform.
=> πr²h = Area of platform × height of platform
=> π × (7/2)² × 308 × h
=> π × 49/4 × 20 = 308 × h
=>h = 22/7 × 49/4 × 20/308
=> h = 11 × 7/2 × 10/154
=> h = 77/2 × 10/154
=> h = 10/4
=> h = 5/2
=> h = 2.5m
Hence, the height of platform is 2.5m.
I hope it will help you.
Regards.
Answer:
Diamter = 7 m
so, radius = 3.5 m
Earth dug out from (cylindrical) well
=π×r×r×h
= 22/7×3.5×3.5×20
=770mcube
to from platform ...... (cuboidal)
volume of cuboid = l×b×h
770=22×14×h
so, height = 770/22×14=2.5m