Please help wuth math 25 points

alexandr402 [8]

-1 is the answer homie

7 0

3 years ago

A ladder 10 m long,leans against a vertical wall at an angle of 70° to the ground.if the ladder slips down the wall 4m,find,corr

lina2011 [118]

Answer:

(a) the new angle the ladder makes with the ground is $32.7^o$

(b) the ladder slipped back about 5 meters

Step-by-step explanation:

Notice that the ladder doesn't change its length in the process.

So let's start from the initial situation , finding the distance from the ground at which the ladder touches the wall when the angle with the ground is 70^o. Notice that this situation is represented by a right angle triangle with the right angle between the wall and the ground (see attached image), and that we can use the sine function to find the side opposite to the 70 degree angle:

$sin(70^o)=\frac{opposite}{hypotenuse} \\sin(70^o)=\frac{h}{10}\\h=10\, sin(70^o) \approx 9.4 \,\,m$

therefore 9.4 meters is approximately the height at which the ladder touches the wall initially.

Now, if the tip of the ladder goes down the wall 4 meters, it is now at 9.4 m - 4 m = 5.4 m from the ground. We can therefore use again the sine function to solve for the new angle:

$sin(x)=\frac{opposite}{hypotenuse} \\sin(x)=\frac{5.4}{10} \\sin(x)=0.54\\x=arcsin(0.54)\\x= 32.7^o$

To answer the second question we need to find the original distance from the wall that the bottom of the ladder was originally, and for that we can use the cosine function:

$cos(70^o)=\frac{adjacent}{hypotenuse} \\cos(70^o)=\frac{x}{10}\\x=10\,cos(70^o)\\x\approx 3.4 \,\,m$

Now fro the new position of the bottom of the ladder relative to the wall:

$cos(32.7^o)=\frac{adjacent}{10} \\adjacent=10\,cos(32.7^o)\\adjacent\approx 8.4\,\,m$

then the difference in between those two distances is what we need:

8.4 m - 3.4 m = 5 m

4 0

3 years ago

Amelie is making a recipe that uses 1 3/4 cups flour. She is making 2 1/2 times the original recipe.

elixir [45]

Answer:

She would need $4\frac{3}{8}$ flour to make $2\frac{1}{2}$ times the recipe.

Step-by-step explanation:

To make 1 recipe Amelia uses = $1 \frac{3}{4}\ cups$ of flour.

So, to make $2\frac{1}{2}$ times the recipe she would need = $1 \frac{3}{4}\times 2\frac{1}{2}$ .

We evaluate the above mixed numbers by converting them to fraction(by multiplying denominator with whole number and adding to numerator and write as fraction of same denominator.).

$=\frac{7}{4}\times \frac{5}{2}$

$=\frac{35}{8}$

Then converting back to mixed number (by dividing the numerator by denominator and writing the quotient as the whole number and the remainder as fraction with same denominator.

$\frac{35}{8}=4\frac{3}{8}$

So, she would need $4\frac{3}{8}$ flour to make $2\frac{1}{2}$ times the recipe.

7 0

3 years ago

What is the definition of distributive property?

anyanavicka [17]

The distributive property is one of the most frequently used properties in math. In general, this term refers to the distributive property of multiplication which states that the. Definition: Thedistributive property lets you multiply a sum by multiplying each addend separately and then add the products.

7 0

4 years ago

Read 2 more answers

Marie made the box plot below to display a set of data. Which set of data could the box plot represent?

Assoli18 [71]

Answer:

see below

Step-by-step explanation:

First of all, you want to find the data set the matches the extreme values of 5 and 35. That eliminates the 2nd and 4th choices.

Then you want to find the data set that has a median of 15. The first data set has a middle value (median) of 20, so that choice is eliminated.

The data set of the 3rd choice matches the box plot extremes, median, and quartile values.

7 0

3 years ago