All categories

3 years ago

A train covers 10 Km in 2 1⁄2 hr. find The speed of the train in Km /hr is a. 4 km /h b. 50 km/h c. 20km /h d. 5 km/h

Mathematics

1 answer:

Luba_88 [7]3 years ago

5 0

Answer:

4km/h

Step-by-step explanation:

the speed is equals to distance/time

distance/time=10km/2.5h

=4kh/h

You might be interested in

Asociologist is studying influences on family size. He finds pairs of sisters, both of whom are married, and determines for each

Mazyrski [523]

Answer:

Step-by-step explanation:

6 0

3 years ago

Use Simpson's Rule with n = 10 to estimate the arc length of the curve. Compare your answer with the value of the integral produ

SOVA2 [1]

$y=\ln(6+x^3)\implies y'=\dfrac{3x^2}{6+x^3}$

The arc length of the curve is

$\displaystyle\int_0^5\sqrt{1+\frac{9x^4}{(6+x^3)^2}}\,\mathrm dx$

which has a value of about 5.99086.

Let $f(x)=\sqrt{1+\frac{9x^4}{(6+x^3)^2}}$ . Split up the interval of integration into 10 subintervals,

[0, 1/2], [1/2, 1], [1, 3/2], ..., [9/2, 5]

The left and right endpoints are given respectively by the sequences,

$\ell_i=\dfrac{i-1}2$

$r_i=\dfrac i2$

with $1\le i\le10$ .

These subintervals have midpoints given by

$m_i=\dfrac{\ell_i+r_i}2=\dfrac{2i-1}4$

Over each subinterval, we approximate $f(x)$ with the quadratic polynomial

$p_i(x)=f(\ell_i)\dfrac{(x-m_i)(x-r_i)}{(\ell_i-m_i)(\ell_i-r_i)}+f(m_i)\dfrac{(x-\ell_i)(x-r_i)}{(m_i-\ell_i)(m_i-r_i)}+f(r_i)\dfrac{(x-\ell_i)(x-m_i)}{(r_i-\ell_i)(r_i-m_i)}$

so that the integral we want to find can be estimated as

$\displaystyle\sum_{i=1}^{10}\int_{\ell_i}^{r_i}p_i(x)\,\mathrm dx$

It turns out that

$\displaystyle\int_{\ell_i}^{r_i}p_i(x)\,\mathrm dx=\frac{f(\ell_i)+4f(m_i)+f(r_i)}6$

so that the arc length is approximately

$\displaystyle\sum_{i=1}^{10}\frac{f(\ell_i)+4f(m_i)+f(r_i)}6\approx5.99086$

5 0

3 years ago

I don't understand how to do this problem. help ? ( number 13)

OverLord2011 [107]

5x- 10 = 20
5x -10 +10 = 20 +10
5x = 30
5x/5 =30/5
x = 6

7 0

3 years ago

Which equation is equivalent to x2+10x+2=0 ?

Svet_ta [14]

x =(10-√92)/2=5-√ 23 = 0.204 or x =(10+√92)/2=5+√ 23 = 9.796

4 0

3 years ago

Some please help with this problem, I have tried multiple time but still couldn't get the right answer. :(

Tanzania [10]

Given data:

Total number of songs = 8

Rock songs = 3

Reggae songs = 2

Country songs = 3

Probability = Number of favorable outcomes / Total number of outcomes

To find:

When song is selected randomly to play first song and then second song from remaining ones ,

Probability when both the songs are from Reggae songs,

$\begin{gathered} P\text{ =}\frac{2}{8}\times\frac{1}{7} \\ \text{ = }\frac{2}{56} \end{gathered}$ $P=\frac{1}{28}$

Thus , the probability is 1/28.

4 0

1 year ago