1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
Fittoniya [83]
3 years ago
15

Mateo wants to make a toy sailboat. He has two pieces of wood to choose from. His first piece of wood is a block that measures 1

8'' x 10" x 8". It weighs 46.65 lbs. His second piece of wood is a log of wood measuring 21" long, with an average circumference of 25.12". It weighs 39.25 lbs. The sailboat needs to float, but both blocks of wood are denser than wood usually is, and he's not sure either piece of wood will float. He doesn't want to get the water wet before he's applied a sealant, so he isn't willing to just drop them in the water to find out.
2a. Which common solid can he use to represent the block? Which common solid can he use to represent the log? (2 points)
2b. What is the density of the block in pounds per cubic inch? Give the formula for density and show your work. (3 points)
2c. What is the density of the log in pounds per cubic inch? Give the formula for density and show your work. Use 3.14 for π. (Hint: you can determine the radius from the circumference.) (3 points)
2d. Water has a density of about 0.0361 pounds/cubic inch. Anything rarer will float, and anything denser will sink. Which of the pieces of wood are suitable for making a toy boat that will float? (2 points)
Mathematics
1 answer:
Virty [35]3 years ago
3 0

Step-by-step explanation:

2a. The block of wood has the shape of a rectangular prism.  The log has the shape of a cylinder.

2b. Density is mass divided by volume.  We know the mass, but we need to find the volume.

Volume of a rectangular prism is:

V = whl

where w is the width, h is the height, and l is the length

V = (18)(10)(8)

V = 1440 in³

So the density is:

d = 46.65 lbs / 1440 in³

d = 0.0324 lb/in³

2c.  Volume of a cylinder is:

V = πr²h

where r is radius and h is height.

The circumference is C = 2πr, so r = C / (2π).

r = 25.12 / (2*3.14)

r = 4.00

V = 3.14 (4.00)² (21)

V = 1055.04 in³

So the density is:

d = 39.25 lb / 1055.04 in³

d = 0.0372 lb/in³

2d.  The block is less dense than water; the log is more dense than water.  So he should make the boat out of the block.

You might be interested in
What is 8/10 as a percentage
STatiana [176]
Your answer would be 80%
6 0
3 years ago
Read 2 more answers
On the following number line, two rational numbers are graphed.Represent the two numbers as fractions (or mixed numbers) in lowe
nordsb [41]
The first graphed rational number is at the middle of -2 and -1, thus the number represented is -1 \frac{1}{2}

The second graphed number is five out of six places from from 0 to 1, thus the number graphed is 0+ \frac{5}{6} = \frac{5}{6}

The difference between the two numbers can be represented as
-1 \frac{1}{2} - \frac{5}{6}
or
\frac{5}{6} -(-1 \frac{1}{2} )= \frac{5}{6} +1 \frac{1}{2}

To find the difference,

-1 \frac{1}{2} - \frac{5}{6} \\ \\ =-1 \frac{3+5}{6}  \\  \\ =-1 \frac{8}{6} =-2 \frac{2}{6}  \\  \\ =-2 \frac{1}{3}

Also,

\frac{5}{6} +1 \frac{1}{2} \\  \\ =1 \frac{5+3}{6}  \\  \\ =1 \frac{8}{6} =2 \frac{2}{6}  \\  \\ =2 \frac{1}{6}
4 0
3 years ago
PLEASE HURRY 12 POINTS PLEASE HELPPPPPP
GalinKa [24]

Step-by-step explanation:

to find the area of a circle, it is pi times radius squared. so 1 times pi squared is pi^2 the area is 4 plus 2pi^2

6 0
2 years ago
A lake contains 4 distinct types of fish. Suppose that each fish caught is equally likely to be any one of these types. Let Y de
gregori [183]

a= μ-3.16*σ , b= μ+3.16*σ if each fish caught is equally likely to be any one of these 4 distinct types.

<h3>What is meant by Chebyshev inequality?</h3>

Chebyshev's inequality is a probability theory that ensures that, over a vast range of probability distributions, no more than a particular proportion of values would be present within a selected limits or range as from mean. In other words, only a certain fish caught will be discovered within a given range of the distribution's mean.

The formula for which no more than a particular number of values can exceed is 1/K2; in other words, 1/K2 of a distribution's values can be more than or equal to K standard deviations away from the distribution's mean. Furthermore, it asserts that 1-(1/K2) of a distribution's values must be within, but not include, K standard deviations of the distribution's mean.

How to solve?

from Chebyshev's inequality for Y

P(| Y - μ|≤ k*σ ) ≥ 1-1/k²

where

Y =  the number of fish that need be caught to obtain at least one of each type

μ = expected value of Y

σ = standard deviation of Y

P(| Y - μ|≤ k*σ ) = probability that Y is within k standard deviations from the mean

k= parameter

thus for

P(| Y - μ|≤ k*σ ) ≥ 1-1/k²

P{a≤Y≤b} ≥ 0.90 →  1-1/k² = 0.90 → k = 3.16

then

P(μ-k*σ≤ Y ≤ μ+k*σ ) ≥ 0.90

using one-sided Chebyshev inequality (Cantelli's inequality)

P(Y- μ≥ λ) ≥ 1- σ²/(σ²+λ²)

P{Y≥b} ≥ 0.90  →  1- σ²/(σ²+λ²)=  1- 1/(1+(λ/σ)²)=0.90 → 3= λ/σ → λ= 3*σ

then for

P(Y≥ μ+3*σ ) ≥ 0.90

In order to learn more about Chebyshev inequality, visit:

brainly.com/question/24971067

#SPJ4

4 0
1 year ago
A telemarketer spent 7 hours during her 8-hour shift calling up new clients. What percentage of her time was spent on things oth
padilas [110]
1/8 of her time was spent on things other than working with clients. 1/8 = 0.125 * 100 = 12.5%
6 0
2 years ago
Other questions:
  • Rita and Alicia are each paid by the hour reader Works 5 and 1/2 hours and earn $77 Eliseo Works 3 3/4 hours and $60 to hourly r
    7·1 answer
  • Which function below is the inverse of f(x)=7x-1/2
    14·1 answer
  • Graph the function y= -1.5x to the second power
    9·2 answers
  • You toss 5 coins. What is the probability that all 5 show heads?
    15·1 answer
  • Van purchased a DVD player on sale. The initial price was ​$175.90175.90. The price after the discount was ​$150.75150.75. What
    8·1 answer
  • The least common multiple is the _____ multiple, other than 0, common to sets of multiples.
    6·1 answer
  • A triangle has side lengths of 14, 23, and 27. Is it a right angle ?
    8·1 answer
  • PLEASE HELP ME OUT WITH THIS ONE!! However, it does not say what the number previously was. BUT PLEASE HELP ME!!!
    13·2 answers
  • Share 747 in the ratio 2:7
    11·1 answer
  • (WILL GIVE BRAINLIST) A student investigated the effect of root space on plant growth. The student grew two groups of plants of
    12·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!