Discussion about math, puzzles, games and fun.   Useful symbols: ÷ × ½ √ ∞ ≠ ≤ ≥ ≈ ⇒ ± ∈ Δ θ ∴ ∑ ∫  π  -¹ ² ³ °

You are not logged in.

#1 2006-11-13 23:17:26

Toast
Real Member
Registered: 2006-10-08
Posts: 1,321

Depth of Water in a cuboid

5 litres of water is poured into a cuboid with base dimensions of 10 cm by 12 cm and a height of 50 cm. What is the depth of water in the cuboid correct to the nearest millimetre?

Offline

#2 2006-11-13 23:56:23

MathsIsFun
Registered: 2005-01-21
Posts: 7,685

Re: Depth of Water in a cuboid

5 litres = 5000 cm[sup]3[/sup]

5000/(10x12) = 41.666... cm = 42 mm (to the mm)

"The physicists defer only to mathematicians, and the mathematicians defer only to God ..."  - Leon M. Lederman

Offline

#3 2006-11-14 00:48:09

Toast
Real Member
Registered: 2006-10-08
Posts: 1,321

Re: Depth of Water in a cuboid

Why, uh, do you divide by (10x12)?

Offline

#4 2006-11-14 02:32:03

mathsyperson
Moderator
Registered: 2005-06-22
Posts: 4,900

Re: Depth of Water in a cuboid

Because that's the base area of the cuboid. The height of water will go up by 1cm for every 120cm³ you pour in, so to find the height you need to divide the volume by that.

Why did the vector cross the road?
It wanted to be normal.

Offline