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3 years ago

A wooden board has a volume of 0.225 cubic m and a mass of 146.25 kilograms.

Mathematics

1 answer:

Triss [41]3 years ago

5 0

Answer:

650 kg/m³

Step-by-step explanation:

The density is the ratio of mass to volume. The volume is the product of the dimensions of the prism.

density = (146.25 kg)/((1.5 m)(0.75 m)(0.2 m)) = 146.25/0.225 kg/m³

= 650 kg/m³

Hope this answer helps you :)

Have a great day

Mark brainliest

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Will mark brainliest for the correct answer!

romanna [79]

Part (a)

Focus on triangle PSQ. We have

angle P = 52

side PQ = 6.8

side SQ = 5.4

Use of the law of sines to determine angle S

sin(S)/PQ = sin(P)/SQ

sin(S)/(6.8) = sin(52)/(5.4)

sin(S) = 6.8*sin(52)/(5.4)

sin(S) = 0.99230983787513

S = arcsin(0.99230983787513)

S = 82.889762826274

Which is approximate

------------

Use this to find angle Q. Again we're only focusing on triangle PSQ.

P+S+Q = 180

Q = 180-P-S

Q = 180-52-82.889762826274

Q = 45.110237173726

Which is also approximate.

A more specific name for this angle is angle PQS, which will be useful later in part (b).

------------

Now find the area of triangle PSQ

area of triangle = 0.5*(side1)*(side2)*sin(included angle)

area of triangle PSQ = 0.5*(PQ)*(SQ)*sin(angle Q)

area of triangle PSQ = 0.5*(6.8)*(5.4)*sin(45.110237173726)

area of triangle PSQ = 13.0074347717966

------------

Next we'll use the fact that RS:SP is 2:1.

This means RS is twice as long as SP. Consequently, this means the area of triangle RSQ is twice that of the area of triangle PSQ. It might help to rotate the diagram so that line PSR is horizontal and Q is above this horizontal line.

We found

area of triangle PSQ = 13.0074347717966

So,

area of triangle RSQ = 2*(area of triangle PSQ)

area of triangle RSQ = 2*13.0074347717966

area of triangle RSQ = 26.0148695435932

------------

We're onto the last step. Add up the smaller triangular areas we found

area of triangle PQR = (area of triangle PSQ)+(area of triangle RSQ)

area of triangle PQR = (13.0074347717966)+(26.0148695435932)

area of triangle PQR = 39.0223043153899

------------

<h3>Answer: 39.0223043153899</h3>

This value is approximate. Round however you need to.

===========================================

Part (b)

Focus on triangle PSQ. Let's find the length of PS.

We'll use the value of angle Q to determine this length.

We'll use the law of sines

sin(Q)/(PS) = sin(P)/(SQ)

sin(45.110237173726)/(PS) = sin(52)/(5.4)

5.4*sin(45.110237173726) = PS*sin(52)

PS = 5.4*sin(45.110237173726)/sin(52)

PS = 4.8549034284642

Because RS is twice as long as PS, we know that

RS = 2*PS = 2*4.8549034284642 = 9.7098068569284

So,

PR = RS+PS

PR = 9.7098068569284 + 4.8549034284642

PR = 14.5647102853927

-------------

Next we use the law of cosines to find RQ

Focus on triangle PQR

c^2 = a^2 + b^2 - 2ab*cos(C)

(RQ)^2 = (PR)^2 + (PQ)^2 - 2(PR)*(PQ)*cos(P)

(RQ)^2 = (14.5647102853927)^2 + (6.8)^2 - 2(14.5647102853927)*(6.8)*cos(52)

(RQ)^2 = 136.420523798282

RQ = sqrt(136.420523798282)

RQ = 11.6799196828694

--------------

We'll use the law of sines to find angle R of triangle PQR

sin(R)/PQ = sin(P)/RQ

sin(R)/6.8 = sin(52)/11.6799196828694

sin(R) = 6.8*sin(52)/11.6799196828694

sin(R) = 0.4587765387107

R = arcsin(0.4587765387107)

R = 27.3081879220073

--------------

This leads to

P+Q+R = 180

Q = 180-P-R

Q = 180-52-27.3081879220073

Q = 100.691812077992

This is the measure of angle PQR

subtract off angle PQS found back in part (a)

angle SQR = (anglePQR) - (anglePQS)

angle SQR = (100.691812077992) - (45.110237173726)

angle SQR = 55.581574904266

--------------

<h3>Answer: 55.581574904266</h3>

This value is approximate. Round however you need to.

8 0

2 years ago

X + 6y = 2 4x - 3y = 10 Pick the first step to solving this system of equations using the addition method.

podryga [215]

<span>This one is the correct answer----->Multiply the bottom equation by 2 thus eliminating the y variable when the equations are added together.

</span><span>X + 6y = 2 ....top
</span><span>4x - 3y = 10...bottom

if we multiply the bottom equation by 2 .......... => 8x - 6y = 20
if we add it to the top one..........>(8+1)x +(6-6)y = (20+2)
then we solve for x => x = 22/9

then with the top equation, we solve for y == > y = -2/27</span>

4 0

2 years ago

Which table shows a proportional relationship between x and y ?

insens350 [35]

Answer:

Table C

Step-by-step explanation:

Given

Table A to D

Required

Which shows a proportional relationship

To do this, we make use of:

$k = \frac{y}{x}$

Where k is the constant of proportionality.

In table (A)

x = 2, y = 4

$k = \frac{y}{x}$

$k = \frac{4}{2}$

$k = 2$

x = 4, y = 9

$k = \frac{y}{x}$

$k = \frac{9}{4}$

$k = 2.25$

Both values of k are different. Hence, no proportional relationship

In table (B)

x = 3, y = 4

$k = \frac{y}{x}$

$k = \frac{4}{3}$

$k = 1.33$

x = 9, y = 16

$k = \frac{y}{x}$

$k = \frac{16}{9}$

$k = 1.78$

Both values of k are different. Hence, no proportional relationship

In table (C):

x = 4, y = 12

$k = \frac{y}{x}$

$k = \frac{12}{4}$

$k = 3$

x = 5, y = 15

$k = \frac{y}{x}$

$k = \frac{15}{5}$

$k = 3$

x = 6, y = 18

$k = \frac{y}{x}$

$k = \frac{18}{6}$

$k = 3$

This shows a proportional relationship because all values of k are the same for this table

7 0

3 years ago

What is greater 66mm or 6cm

LuckyWell [14K]

66mm=6cm
So that means that any 66mm is 6cm point 6mm ===> 66cmm=6.6cm
Thus, 6cm is not greater but it is equal to 66mm
It's like you looking at 1yd=3feet which also means that 3feet=1yd.

7 0

3 years ago

The measure if an exterior angle of a regular polygon is given below find the measure of an interior angle then find the number

zhuklara [117]

Answer:

The measure of the interior angle is 156°

The polygon has 15 sides

Step-by-step explanation:

<em>Let us revise some facts in a polygon</em>

The sum of the exterior angles of any polygon is 360°

At each vertex of a polygon, the exterior and interior angles formed a pair of linear angles (The sum of their measures is 180°)
A regular polygon has equal angles and equal sides

<em>In our question </em>

∵ The measure of an exterior angle of a regular polygon = 24°

∵ The sum of measures of the interior angle and exterior angle at

a vertex of a polygon is 180°

∴ The measure of the interior angle = 180° - 24°

∴ The measure of the interior angle = 156°

∵ The sum of the exterior angles of any polygon is 360°

∵ The polygon is regular (all angles are equal in measures)

∴ The measure of each exterior angle = 360° ÷ n, where n the

number of its angles or sides

∴ 24° = 360°/n

→ Multiply both sides by n

∴ 24n = 360

→ Divide both sides by 24

∴ n = 15

∴ The polygon has 15 sides

5 0

2 years ago