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2 years ago

Can someone please answer these questions?

Mathematics

1 answer:

andrew11 [14]2 years ago

8 0

5.a) since the distance is 140km, and the time is 2hours, and we need the speed in km/h, we have to divide the distance by time, and we will get the speed: s=d/t = 140km/2h = 70km/h

b) the distance is 43km, and the time is 30 minutes, which is 0,5hours, we do the same thing here, with given formula : s=d/t = 43km/0,5h = 86km/h

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Help me please i dont understand

kipiarov [429]

Answer:

C=75.36

A=452.16

Step-by-step explanation:

C=2x3.14xr

$2$ × $\pi$ × $12=75.36$

A=3.14× $r^{2}$

3.14x12x12=452.16

5 0

3 years ago

What Is 5 1/2 - 2 5/6? Explain Your Answer

natulia [17]

Answer:

2 2/3

Step-by-step explanation:

Make them into improper fractions first.

11/2 - 17-6

Then multiply 11/2 so that they have common denominators.

33/6 - 17/6

Then solve.

33/6 - 17/6 = 16/6

Then convert back into a mixed number.

2 4/6 or 2 2/3

5 0

3 years ago

I need help on this one aswell if anyone wants to help me.

Lelechka [254]

Answer:

y=63

Step-by-step explanation:

7 0

2 years ago

Read 2 more answers

Explain how to multiply the following whole numbers 21 x 14

Lesechka [4]

Answer:

$\begin{matrix}\space\space&\textbf{2}&\textbf{1}\\ \times \:&1&\textbf{4}\end{matrix}$

________

$\frac{\begin{matrix}\space\space&\textbf{0}&8&4\\ +&\textbf{2}&1&0\end{matrix}}{\begin{matrix}\space\space&\textbf{2}&9&4\end{matrix}}$

Step-by-step explanation:

Given

$21\:\times \:14$

Line up the numbers

$\begin{matrix}\space\space&2&1\\ \times \:&1&4\end{matrix}$

Multiply the top number by the bottom number one digit at a time starting with the ones digit left(from right to left right)

Multiply the top number by the bolded digit of the bottom number

$\begin{matrix}\space\space&\textbf{2}&\textbf{1}\\ \times \:&1&\textbf{4}\end{matrix}$

Multiply the bold numbers: 1×4=4

$\frac{\begin{matrix}\space\space&2&\textbf{1}\\ \times \:&1&\textbf{4}\end{matrix}}{\begin{matrix}\space\space&\space\space&4\end{matrix}}$

Multiply the bold numbers: 2×4=8

$\frac{\begin{matrix}\space\space&\textbf{2}&1\\ \times \:&1&\textbf{4}\end{matrix}}{\begin{matrix}\space\space&8&4\end{matrix}}$

Multiply the top number by the bolded digit of the bottom number

$\frac{\begin{matrix}\space\space&\textbf{2}&\textbf{1}\\ \times \:&\textbf{1}&4\end{matrix}}{\begin{matrix}\space\space&8&4\end{matrix}}$

Multiply the bold numbers: 1×1=1

$\frac{\begin{matrix}\space\space&\space\space&2&\textbf{1}\\ \space\space&\times \:&\textbf{1}&4\end{matrix}}{\begin{matrix}\space\space&\space\space&8&4\\ \space\space&\space\space&1&\space\space\end{matrix}}$

Multiply the bold numbers: 2×1=2

$\frac{\begin{matrix}\space\space&\space\space&\textbf{2}&1\\ \space\space&\times \:&\textbf{1}&4\end{matrix}}{\begin{matrix}\space\space&\space\space&8&4\\ \space\space&2&1&\space\space\end{matrix}}$

Add the rows to get the answer. For simplicity, fill in trailing zeros.

$\frac{\begin{matrix}\space\space&\space\space&2&1\\ \space\space&\times \:&1&4\end{matrix}}{\begin{matrix}\space\space&0&8&4\\ \space\space&2&1&0\end{matrix}}$

adding portion

$\begin{matrix}\space\space&0&8&4\\ +&2&1&0\end{matrix}$

Add the digits of the right-most column: 4+0=4

$\frac{\begin{matrix}\space\space&0&8&\textbf{4}\\ +&2&1&\textbf{0}\end{matrix}}{\begin{matrix}\space\space&\space\space&\space\space&\textbf{4}\end{matrix}}$

Add the digits of the right-most column: 8+1=9

$\frac{\begin{matrix}\space\space&0&\textbf{8}&4\\ +&2&\textbf{1}&0\end{matrix}}{\begin{matrix}\space\space&\space\space&\textbf{9}&4\end{matrix}}$

Add the digits of the right-most column: 0+2=2

$\frac{\begin{matrix}\space\space&\textbf{0}&8&4\\ +&\textbf{2}&1&0\end{matrix}}{\begin{matrix}\space\space&\textbf{2}&9&4\end{matrix}}$

Therefore,

$\begin{matrix}\space\space&\textbf{2}&\textbf{1}\\ \times \:&1&\textbf{4}\end{matrix}$

________

$\frac{\begin{matrix}\space\space&\textbf{0}&8&4\\ +&\textbf{2}&1&0\end{matrix}}{\begin{matrix}\space\space&\textbf{2}&9&4\end{matrix}}$

6 0

2 years ago

The inverse variation equation shows the relationship between wavelength in meters, x, and frequency, y.

wolverine [178]

Answer:

$\lambda=10^{-10}\ m$

Step-by-step explanation:

Given that,

The frequency of x-rays, $f=3\times 10^{18}\ Hz$

We need to find the wavelength for x-rays. The relation between wavelength, frequency and speed of light is given by :

$v=f\lambda\\\\\lambda=\dfrac{c}{f}\\\\\lambda=\dfrac{3\times 10^{8}}{3\times 10^{18}}\\\\=10^{-10}\ m$

So, the wavelength for x-rays is $10^{-10}\ m$ .

7 0

2 years ago