How to make a concrete boat float? 30x30x50 cm?

i need to make a concrete boat.
i am not sure what materials to use
please reply
even for 50x 30x30cm is also okay
it has to float and it should withstand weight by adding sand

Fast, small, Sailboats?

Hello,
I am looking for a small fast sailboat. Here are the requirements that it must fit.
-Hull speed of at least 12 knots
-bigger than 14′ but not bigger than 25′
- No inside cabin
-Furling Jib and maybe a furling stretcher might be nice. :)
- Lest than 20k USD
I love trimarans if you want a better idea of what i am looking for check out this slick boat made by motive trimarans .http://www.motivetrimarans.com/motive25.html I would love this but I believe it costs 80k.
Thank’s so much.

All about Music!! please help me!!?

1.The Winds, Brass, Strings and Percussion refer to the
2.The “staff” in music refers to the
3.When a piece of music changes key in the middle it is called
4.In Benjamin Brittenʼs Young Persons Guide to the Orchestra the original theme was written by
The Young Personʼs Guide to the Orchestra is in what form ?
5.The clarinet, oboe , flute and Bassoon are members of which family of instruments?
6.Forte and piano are examples of what in music?
7.The distance between any 2 notes of music is called
8.Musical notation that notates a silence is called a
9.The quality or distinct sound of a musical instrument is referred to as
10.When music goes from piano to forte fairly gradually it is called a
11.A melody sung with only one part and no accompaniment is called
12.When 2 or more melodies or musical voices are played or sung simultaneously the texture is described as
13.The sheet music that shows what everyone in a group is playing simultaneously is, and is looked at by a conductor is called
14.The technique of playing a string instrument with a bow is called
15.The technique of plucking a stringed instrument is called
16.The trumpet, trombone, horn and tuba are members of which family of instruments?
17.The xylophone, glockenspiel, piano, and timpani are examples of
18.Any recurring pattern of strong beats and weak beats is called a
19.In music the term “tempo” refers to
20.The simplest 3 note chord is called a
21.The piano is a member of which family of instruments
22.One small section of music in the meter of a piece that is separated by lines is called a
23.The scale that uses both the white notes and the black notes on the piano, all 12 pitches of the octave is called
( I really need some help with those questions, help me please!! Thank you very much!!)

I need Help with this MATH problem?

(Question 1) BMW oracle’s USA trimaran boat, with top speed of 45 knots, won the America’s cup in 2010. It’s top speed is 5 knots more than 2.5 times the top speed of BMW oracle’s 2007 cup monohull. Find the top speed of BMW oracle’s 2007 cup entry

(Question 2) Morgan seeds has a rectangular test plot with a perimeter of 322m. The length is 25m more than the width. Find the dimensions of the plot.

(Question 3) Erica invested a total of $5000, part at 3% simple interest and part at 4% simple interest. At the end of 1 year, the investment had earned $176 interest. How much was invested at each rate .

help with this MATH problem?

(Question 1) BMW oracle’s USA trimaran boat, with top speed of 45 knots, won the America’s cup in 2010. It’s top speed is 5 knots more than 2.5 times the top speed of BMW oracle’s 2007 cup monohull. Find the top speed of BMW oracle’s 2007 cup entry

(Question 2) Morgan seeds has a rectangular test plot with a perimeter of 322m. The length is 25m more than the width. Find the dimensions of the plot.

(Question 3) Erica invested a total of $5000, part at 3% simple interest and part at 4% simple interest. At the end of 1 year, the investment had earned $176 interest. How much was invested at each rate .