Q.

The external length, breadth and height of a closed rectangular wooden box are 18 cm,10 cm   and 6 cm   respectively and thickness of wood is 1/2 cm  .When the box is empty it weighs 15 kg   and when filled with sand it weighs 100 kg.   Find the weight of the cubic cm of wood and cubic cm of sand.


see full answer

Start JEE / NEET / Foundation preparation at rupees 99/day !!

21% of IItians & 23% of AIIMS delhi doctors are from Sri Chaitanya institute !!
An Intiative by Sri Chaitanya

a

1 21 kg  , 1 9 kg  

b

1 15 kg  , 0.10kg  

c

1 12 kg  , 0.20kg  

d

1 25 kg  , 0.5kg   

answer is A.

(Unlock A.I Detailed Solution for FREE)

Ready to Test Your Skills?

Check your Performance Today with our Free Mock Test used by Toppers!

Take Free Test

Detailed Solution

Given that, length, breadth and height of the rectangular box is Question Image, Question Image and Question Image.
The volume of a cube is expressed as, V=lbh   where l, b and h be the length, width and height of a cube.
Thus, the volume of a rectangular block is,
Question ImageSince, the thickness of the wood is 1 2  , so the length, breadth and height of the wooden block is,
Question ImageSimilarly,
Question ImageAnd,
Question ImageThus, the volume of hollow space in rectangular block is,
Question ImageSo, the volume of rectangular wood is,
Question ImageSince the weight of the empty box is Question Image, thus the weight of a cubic cm of wood is,
W= w V s W= 15 365 W= 1 21  
Since the weight of box filled with sand is w=100kg  , so, the weight of a cubic cm of sand is,
W= weight of sandweight of empty box Volume of hollow space   W= 10015 765 W = 1 9 kg  
Thus, the weight of a cubic cm of wood is 1 21 kg   and weight of a cubic cm of sand is 1 9 kg.  
Therefore, option (1) is correct.
 
Watch 3-min video & get full concept clarity

tricks from toppers of Infinity Learn

score_test_img

Get Expert Academic Guidance – Connect with a Counselor Today!

whats app icon