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2 years ago

Pierre's unicycle wheel has a diameter of 80 cm.

Mathematics

1 answer:

yaroslaw [1]2 years ago

4 0

a) The distance covered during one rotation is 251.20 cm

b) The wheel must complete 40 rotations to covera distance of 100m

Step-by-step explanation:

It is to be understood that a circle when rotated covers a distance equalling its circumference in one rotation.

a) Given the diameter of the cycle’s wheel= 80 cm

Radius of the wheel= 40cm (r= diameter/2)

Circumference of the wheel= 2*3.14*40= 251.20 cm

Distance covered by the wheel in one rotation is 251.2 cm

b) Distance to be covered during competition= 100m

We know that 1 m equals 100 cm Hence, 100 m would equal 10,000 cm

This distance would be covered in successive revolutions of the wheel. Let the wheel make “n” revolutions

Hence distance covered during one revolution* no of revolution= total distance to be covered

251.2n= 10,000

n =10,000/251.2= 38.81

When rounded to the nearest whole number, “n” equals 40

Hence no of revolutions by the wheel is 40

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A 16-inch candle is lit and burns at a constant rate of 0.8 inches per hour. Let t represent the number of hours since the candl

Tamiku [17]

Answer:

<h2>See the explanation.</h2>

Step-by-step explanation:

The initial length of the candle is 16 inch. It also given that, it burns with a constant rate of 0.8 inch per hour.

After one hour since the candle was lit, the length of the candle will be (16 - 0.8) = 15.2 inch.

After two hour since the candle was lit, the length of the candle will be (15.2 - 0.8) = 14.4 inch. The length of the candle after two hours can also be represented by {16 - 2(0.8)}.

Hence, the length of the candle after t hours when it was lit can be represented by the function, $f(t) = 16 - 0.8t$ . $f(t) = 0$ at t = 20.

The domain of the function is 0 to 20.

The range is 0 to 16.

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2 years ago

18% of the the students at a school are in year 8 and 16% of the students are in year 9. If the school has 126 tera 8 students,

yarga [219]

Answer:

112

Step-by-step explanation:

The general form of all percentage questions is: the chunk= (some percentage) (of the whole), or c=p*w

We know that 18% of students are 8th grade and that is 126 students, so p = 0.18 and c=126 (126 students are 18% of the whole school)

126 = (0.18)w, divide both sides by 0.18

126/(0.18) = w = 700

9th graders are 16% of the school or 16% of 700 students

c = (0.16) 700 = 112 students

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2 years ago

You bought $2000 worth of stocks in 2012. The value of the stocks has been decreasing by 10% each year. What will your stock be

goblinko [34]

Answer:

that is the solution to the question

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2 years ago

Steve likes to entertain friends at parties with "wire tricks." Suppose he takes a piece of wire 60 inches long and cuts it into

Alex_Xolod [135]

Answer:

a) the length of the wire for the circle = $(\frac{60\pi }{\pi+4}) in$

b)the length of the wire for the square = $(\frac{240}{\pi+4}) in$

c) the smallest possible area = 126.02 in² into two decimal places

Step-by-step explanation:

If one piece of wire for the square is y; and another piece of wire for circle is (60-y).

Then; we can say; let the side of the square be b

so 4(b)=y

b= $\frac{y}{4}$

Area of the square which is L² can now be said to be;

$A_S=(\frac{y}{4})^2 = \frac{y^2}{16}$

On the otherhand; let the radius (r) of the circle be;

2πr = 60-y

$r = \frac{60-y}{2\pi }$

Area of the circle which is πr² can now be;

$A_C= \pi (\frac{60-y}{2\pi } )^2$

$=( \frac{60-y}{4\pi } )^2$

Total Area (A);

A = $A_S+A_C$

= $\frac{y^2}{16} +(\frac{60-y}{4\pi } )^2$

For the smallest possible area; $\frac{dA}{dy}=0$

∴ $\frac{2y}{16}+\frac{2(60-y)(-1)}{4\pi}=0$

If we divide through with (2) and each entity move to the opposite side; we have:

$\frac{y}{18}=\frac{(60-y)}{2\pi}$

By cross multiplying; we have:

2πy = 480 - 8y

collect like terms

(2π + 8) y = 480

which can be reduced to (π + 4)y = 240 by dividing through with 2

$y= \frac{240}{\pi+4}$

∴ since $y= \frac{240}{\pi+4}$ , we can determine for the length of the circle ;

60-y can now be;

= $60-\frac{240}{\pi+4}$

= $\frac{(\pi+4)*60-240}{\pi+40}$

= $\frac{60\pi+240-240}{\pi+4}$

= $(\frac{60\pi}{\pi+4})in$

also, the length of wire for the square (y) ; $y= (\frac{240}{\pi+4})in$

The smallest possible area (A) = $\frac{1}{16} (\frac{240}{\pi+4})^2+(\frac{60\pi}{\pi+y})^2(\frac{1}{4\pi})$

= 126.0223095 in²

≅ 126.02 in² ( to two decimal places)

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2 years ago

Suppose an automobile manufacturer designed a radically new lightweight engine and wants to recommend the grade of gasoline that

Deffense [45]

Answer:

The F-statistic used to test the hypothesis that the miles per gallon for each fuel are the same is 4.07.

Step-by-step explanation:

There are four treatments in the data given, i.e. k = 4.

Total number of observations, n = 12.

Note: degrees of freedom is denoted as df.

For treatment, the degrees of freedom = k-1 = 4-1 =3 df.

The total degrees of freedom = n-1 = 12-1 = 11 df.

The error in degrees of freedom = df (total) - df(treatment)

The error in degrees of freedom = 11 - 3 = 8 df

At α = 0.05 level,from the F table, the F-statistic with (3 , 8)df is 4.07.

Therefore, the F-statistic used to test the hypothesis that the miles per gallon for each fuel are the same is 4.07.

8 0

2 years ago