Forest

Nepal is a small country but rich in biological diversity. About 53.3% of the total land area of Nepal is covered by forest. This note provides us an information on forests and its importance.

Summary

Nepal is a small country but rich in biological diversity. About 53.3% of the total land area of Nepal is covered by forest. This note provides us an information on forests and its importance.

Things to Remember

  • Nepal is a small country but rich in biological diversity.
  • About 53.3% of the total land area of Nepal is covered by forest.
  • Forests provide 75% of the total energy consumed in the country (fuel wood) and more than 40% of fodder for livestock is extracted from forests.
  • Forest offers watershed protection, timber and non-timber products, and various recreational options.
  • Harro, barro, bojo, sarpagandha, jatamasi (spikenard), panchaunle, yachagumba are protected medicinal herbs.

MCQs

No MCQs found.

Subjective Questions

Q1:

Find the co-ordinates of the mid point of the line segement joining the given points, (4, 6) and (2, 4).


Type: Short Difficulty: Easy

Show/Hide Answer
Answer: <p>Solution:</p> <p>Here,<br>(4, 6) = (x<sub>1</sub>, y<sub>1</sub>)<br>(2, 4) = (x<sub>2</sub>, y<sub>2</sub>)<br>The co-ordinates of the mid point = (\(\frac{x_1 + x_2}{2}\), \(\frac{y_1 + y_2}{2}\))<br>= (\(\frac{4+ 2}{2}\), \(\frac{6 + 4}{2}\))<br>= (\(\frac{6}{2}\), \(\frac{10}{2}\))<br>= (3, 5)</p> <p>\(\therefore\) The co-ordinates of given mid point is (3, 5).</p>

Q2:

Find the co-ordinates of the point (2, 3) and (7, 3) which divides the line segment joining the following points in the 3:2 ratio.


Type: Short Difficulty: Easy

Show/Hide Answer
Answer: <p>Solution:</p> <p>Here,<br>(2, 3) = (x<sub>1</sub>, y<sub>1</sub>)<br>(7, 3) = (x<sub>2</sub>, y<sub>2</sub>)<br>m<sub>1</sub> : m<sub>2</sub> = 3 : 2<br>Now,<br>or, (x, y) = (\(\frac{m_1 x_2 + m_2 x_1}{m_1 + m_2}\), \(\frac{m_1 y_2 + m_2 y_1}{m_1 + m_2}\))<br>or, (x, y) = (\(\frac{3\times7 + 2\times2}{3 + 2}\), \(\frac{3\times3 + 2\times3}{3 + 2}\))<br>or, (x, y) = (\(\frac{21 + 4}{5}\), \(\frac{9 + 6}{5}\))<br>or, (x, y) = (\(\frac{25}{5}\), \(\frac{15}{5}\))<br>or, (x, y) = (5, 3)<br>So, the required point is (5, 3).</p>

Q3:

The mid point of a line is (0, 3) and one end of the line is (−6, 8). Find the co-ordinates of the other end.


Type: Long Difficulty: Easy

Show/Hide Answer
Answer: <p>Solution:</p> <p>(0, 3) = (x, y)<br>(-6, 8) = (x<sub>1</sub>, y<sub>1</sub>)<br>Let co-ordinates of other end be (x<sub>2</sub>, y<sub>2</sub>)<br>Now,<br>or, x = \(\frac{x_1 + x_2}{2}\)<br>or, 0 = \(\frac{-6 + x_2}{2}\)<br>or, 0 = - 6 + x<sub>2</sub><br>\(\therefore\) x<sub>2 = </sub>6<sub><br></sub>Again,<br>or, y = \(\frac{y_1 + y_2}{2}\)<br>or, 3 = \(\frac{8 + y_2}{2}\)<br>or, 6 = 8 + y<sub>2</sub><br>or, 6 - 8 = y<sub>2</sub><br>\(\therefore\) y<sub>2</sub>= -2</p> <p>So, the co-ordinates of other end is (6, -2).</p>

Q4:

Find the ratio the line joining the points (2, 2) and (−2, −2) is divided by the point (\(\frac{6}{7}\), \(\frac{6}{7}\)) ?


Type: Long Difficulty: Easy

Show/Hide Answer
Answer: <p>Solution:</p> <p>Given,<br>(2, 2) = (x<sub>1</sub>, y<sub>1</sub>)<br>(-2,-2) = (x<sub>2</sub>, y<sub>2</sub>)<br>(x, y) = (\(\frac{6}{7}\), \(\frac{6}{7}\))<br>m<sub>1</sub> : m<sub>2</sub> = ?<br>By using section formula,<br>or, x = \(\frac{m_1 x_2 + m_2 x_1}{m_1 + m_2}\)<br>or, \(\frac{6}{7}\) =\(\frac{m_1 \times(- 2) + m_2 \times 2}{m_1 + m_2}\)<br>or, 6(m<sub>1</sub>+ m<sub>2</sub>) = 7(-2m<sub>1</sub> + 2m<sub>2</sub>)<br>or, 6m<sub>1</sub>+ 6m<sub>2</sub> = -14m<sub>1</sub> + 14m<sub>2<br></sub>or, 6m<sub>1</sub>+ 14m<sub>1</sub>=14m<sub>2 </sub>-6m<sub>2</sub><br>or, 20m<sub>1</sub> = 8m<sub>2</sub><br>or, \(\frac{m_1}{m_2}\) = \(\frac{8}{20}\)<br>\(\therefore\) m<sub>1</sub> : m<sub>2</sub>= 2 : 5<br>Now,<br>or, y = \(\frac{m_1 y_2 + m_2 y_1}{m_1 + m_2}\)<br>or, \(\frac{6}{7}\) = \(\frac{2\times (-2)+ 5\times2}{2 + 5}\)<br>or, \(\frac{6}{7}\) = \(\frac{(-4)+ 10}{7}\)<br>or, \(\frac{6}{7}\) = \(\frac{6}{7}\) <br>\(\therefore\) The required ratio is 2 : 5.</p>

Q5:

Find the ratio in which the y-axis divides the line segment joining the points (−4, 1) and (10, 1)?


Type: Short Difficulty: Easy

Show/Hide Answer
Answer: <p>Solution:</p> <p>Let the points on y-axis be (0, y) which divides the line joining the points<br>(-4, 1) = (x<sub>1</sub>, y<sub>1</sub>) and (10, 1) = (x<sub>2</sub>, y<sub>2</sub>)<br>m<sub>1</sub> : m<sub>2</sub> = ?<br>By using sectional formula<br>or, x = \(\frac{m_1 x_2 + m_2 x_1}{m_1 + m_2}\)<br>or, 0 =\(\frac{m_1 \times10+ m_2 \times(-4)}{m_1 + m_2}\)<br>or, 0 = 10m<sub>1 </sub>- 4m<sub>2</sub><br>or, \(\frac{m_1}{m_2}\) = \(\frac{4}{10}\)<br>or, \(\frac{m_1}{m_2}\) = \(\frac{2}{5}\)<br>\(\therefore\) m<sub>1</sub> : m<sub>2</sub> = 2 : 5</p>

Q6:

Find the ratio in which x-axis divides the line segment joining the points (3, 2) and (3, −9)?


Type: Short Difficulty: Easy

Show/Hide Answer
Answer: <p>Solution:</p> <p>Let the points on y-axis be (x, 0) which divides the line joining the point<br> (3, 2) = (x<sub>1</sub>, y<sub>1</sub>)<br>(3,-9) = (x<sub>2</sub>, y<sub>2</sub>)<br>m<sub>1</sub> : m<sub>2</sub>= ?<br>By using section formula,<br>or, y = \(\frac{m_1 y_2 + m_2 y_1}{m_1 + m_2}\)<br>or, 0 =\(\frac{m_1\times(-9)+ m_2 \times2}{m_1 + m_2}\)<br>or, 0 = -9m<sub>1</sub>+ 2m<sub>2</sub><br>or, \(\frac{m_1}{m_2}\) = \(\frac{2}{9}\)<br>\(\therefore\)m<sub>1</sub> : m<sub>2</sub>= 2 : 9<br><br></p>

Q7:

Find the co-ordinates of the mid point of the line segment joining the given points (5a, 7b) and (3a, −2b).


Type: Short Difficulty: Easy

Show/Hide Answer
Answer: <p>Solution:</p> <p>Given,<br>(5a, 7b) = (x<sub>1</sub>, y<sub>1</sub>)<br>(3a,-2b) = (x<sub>2</sub>, y<sub>2</sub>)<br>Co-ordinates of mid point = (\(\frac{x_1 + x_2}{2}\), \(\frac{y_1 + y_2}{2}\))<br>= (\(\frac{5a + 3a}{2}\), \(\frac{7b- 2b}{2}\))<br>= (\(\frac{8a}{2}\), \(\frac{5b}{2}\))<br>= (4a, \(\frac{5b}{2}\))</p>

Q8:

Find the co-ordinates of the point which divides the line segment joining the (2, −4) and (−3, 6) points in the 2:3 ratio.


Type: Short Difficulty: Easy

Show/Hide Answer
Answer: <p>Solution:</p> <p>(2,-4) = (x<sub>1</sub>, y<sub>1</sub>)<br>(-3, 6) = (x<sub>2</sub>, y<sub>2</sub>)<br>m<sub>1</sub> : m<sub>2</sub> = 2 : 3<br>Now,<br>or, (x, y) = (\(\frac{m_1 x_2 + m_2 x_1}{m_1 + m_2}\), \(\frac{m_1 y_2 + m_2 y_1}{m_1 + m_2}\))<br>or, (x, y) = (\(\frac{2\times (-3) + 3\times2}{2 +3}\), \(\frac{2\times6 + 3\times (-4)}{2 + 3}\))<br>or,(x, y) = (\(\frac{- 6+ 6}{5}\), \(\frac{12-12}{5}\))<br>or, (x, y) = (0, 0)<br>\(\therefore\)The required point is (0, 0).<br><br></p>

Q9:

The mid ppoint of a line is (−4, −5) and one end of the line is (−5, −3). Find the co-ordinates of the other end.


Type: Long Difficulty: Easy

Show/Hide Answer
Answer: <p>Solution:</p> <p>(-4, -5) = (x, y)<br> (-5, -3) = (x<sub>1</sub>, y<sub>1</sub>)<br>Let the co-ordinates of the other end be (x<sub>2</sub>, y<sub>2</sub>)<br>or, x = \(\frac{x_1 + x_2}{2}\)<br>or, -4 = \(\frac{-5 + x_2}{2}\)<br>or, -8 = -5 + x<sub>2</sub><br>or, -8 + 5 = x<sub>2</sub><br>or, x<sub>2</sub> = -3<br>Again, <br>or, y = \(\frac{y_1 + y_2}{2}\)<br>or, -5 = \(\frac{-3 + y_2}{2}\)<br>or, -10 = -3 + y<sub>2</sub><br>or, y<sub>2</sub> = -10 + 3<br>or, y<sub>2</sub> = -7</p> <p>\(\therefore\) The required point(x<sub>2</sub>, y<sub>2</sub>) = (-3, -7)</p> <p></p>

Q10:

In what  ratio  the line joining the points (2, -4) and (-3, 6) is divided by the point (0, 0) ?


Type: Long Difficulty: Easy

Show/Hide Answer
Answer: <p>Solution:</p> <p>(2, -4) = (x1, y1)<br>(-3, 6) = (x2, y2)<br>(0, 0) = (x, y)<br>By using section formula<br>or, x = \(\frac{m_1 x_2 + m_2 x_1}{m_1 + m_2}\)<br>or, 0 = \(\frac{m_1 \times\ (-3) + m_2 \times 2}{m_1 + m_2}\)<br>or, 0 = \(\frac{-3m_1 + 2m_2}{m_1 + m_2}\)<br>or, 0 = -3m<sub>1</sub> + 2m<sub>2</sub><br>or, 3m<sub>1</sub> = 2m<sub>2</sub><br>or, \(\frac{m_1}{m_2}\) = \(\frac{2}{3}\)<br>\(\therefore\) m<sub>1</sub> : m<sub>2</sub> = 2 : 3<br>Now,<br>or, y = \(\frac{m_1 y_2 + m_2 y_1}{2 + 3}\)<br>or, 0 = \(\frac{2 \times\ 6 + 2\times\ (-4)}{m_1 + m_2}\)<br>or, 0 = \(\frac{12 - 12}{5}\)<br>or, 0 = 0<br>\(\therefore\) The required ratio is 2 : 3</p>

Q11:

Find the co-ordinates of the point which divides the line segment joining (-10, 12) and (-3, -9) points in the 4:3 ratio.


Type: Short Difficulty: Easy

Show/Hide Answer
Answer: <p>Solution:</p> <p>(-10, 12) = (x<sub>1</sub>, y<sub>1</sub>)<br>(-3, -9) = (x<sub>2</sub>, y<sub>2</sub>)<br>m<sub>1</sub> ; m<sub>2</sub> = 4 : 3<br>Now,<br>or, (x, y) = (\(\frac{m_1 x_2 + m_2 x_1}{m_1 + m_2}\), \(\frac{m_1 y_2 + m_2 y_1}{m_1 + m_2}\))<br>or, (x, y) = (\(\frac{4 \times(-3) + 3 \times(-10)}{4 + 3}\), \(\frac{4 \times(-9) + 3 \times12}{4 + 3}\))<br>or, (x, y) = (\(\frac{-12 - 30}{7}\), \(\frac{-36 + 36}{7}\))<br>or, (x, y) = (-6, 0)<br>\(\therefore\) The required points are (-6, 0)</p>

Q12:

Find the co-ordinates of the mid point of the line segment joining the (8, 5) and (-12, -7) points.


Type: Short Difficulty: Easy

Show/Hide Answer
Answer: <p>Solution:</p> <p>(8, 5) = (x<sub>1</sub>, y<sub>1</sub>)<br>(-12, -7) = (x<sub>2</sub>, y<sub>2</sub>)</p> <p>Co-ordinates of the mid point = (\(\frac{x_1 + x_2}{2}\), \(\frac{x_1 + y_2}{2}\))<br>= (\(\frac{8 - 12}{2}\), \(\frac{5 - 7}{2}\))<br>= (\(\frac{- 4}{2}\), \(\frac{- 2}{2}\))<br>= (-2, -1)</p>

Q13:

If the ratio of line joining points (-1, 3) and (4, 8) is divided by the point (2 6) ?


Type: Long Difficulty: Easy

Show/Hide Answer
Answer: <p>Solution:</p> <p>(-1, 3) = (x<sub>1</sub>, y<sub>1</sub>)<br> (4, 8) = (x<sub>2</sub>, y<sub>2</sub>)<br>(2, 6) = (x, y)<br>By using section formula<br>or, x = \(\frac{m_1 x_2 + m_2 x_1}{m_1 + m_2}\)<br>or, 2 = \(\frac{m_1 \times\ 4 + m_2 \times\ (-1)}{m_1 + m_2}\)<br>or, 2(m<sub>1</sub> + m<sub>2</sub>) = 4m<sub>1</sub> - 1m<sub>2</sub><br>or, 2m<sub>1</sub> + 2m<sub>2</sub> = 4m<sub>1</sub> - 1m<sub>2</sub><br>or, 2m<sub>1</sub>- 4m<sub>1</sub> = -1m<sub>2</sub> - 2m<sub>2</sub><br>or, -2m<sub>1</sub> = -3m<sub>2</sub><br>Now,<br>or, y = \(\frac{m_1 y_2 + m_2 y_1}{m_1 + m_2}\)<br>or, 6 = \(\frac{-3\times8 + (-2)\times\ 3}{-3 + (-2)}\)<br>or, 6 = \(\frac{-24 -6}{-3 - 2}\)<br>or, 6 = \(\frac{-30}{-5}\)<br>or, -30 = -30</p> <p>\(\therefore\) The required ratio is (-3, -2)</p>

Q14:

Find the co-ordinates of the mid point of the line segment joining (-3, -7) and (-5, -3) points.


Type: Short Difficulty: Easy

Show/Hide Answer
Answer: <p>Solution:</p> <p>Given,<br>(-3, -7) = (x<sub>1</sub>, y<sub>1</sub>)<br> (-5, -3) = (x<sub>2</sub>, y<sub>2</sub>)<br>Co-ordinates of the mid point = (\(\frac{x_1 + x_2}{2}\), \(\frac{y_1 + y_2}{2}\))<br>= (\(\frac{-3 + (-5)}{2}\), \(\frac{-7 + (-3)}{2}\))<br>= (\(\frac{-3 - 5}{2}\), \(\frac{-7 - 3}{2}\))<br>= (\(\frac{-8}{2}\), \(\frac{-10}{2}\))<br>= (-4, -5)</p>

Q15:

Find the co-ordinates of the point which divides the line segment joining (2, 2) and (-2, -2) points in the 2:5 ratios.


Type: Short Difficulty: Easy

Show/Hide Answer
Answer: <p>Solution:</p> <p>(2, 2) = (x<sub>1</sub>, y<sub>1</sub>)<br>(-2, -2) = (x<sub>2</sub>, y<sub>2</sub>)<br>m<sub>1</sub> : m<sub>2</sub> = 2 : 5<br>now,<br>or, (x, y) = (\(\frac{m_1 x_2 + m_2 x_1}{m_1 + m_2}\), \(\frac{m_1 y_2 + m_2 y_1}{m_1 + m_2}\))<br>or, (x, y) = (\(\frac{2 \times\ (-2) + 5 \times\ 2}{2 + 5}\), \(\frac{2 \times\ (-2) + 5 \times\ 2}{2 + 5}\))<br>or, (x, y) = (\(\frac{-4 + 10}{7}\), \(\frac{-4 + 10}{7}\))<br>or, (x, y) = (\(\frac{6}{7}\), \(\frac{6}{7}\))</p> <p>\(\therefore\) The required points is (\(\frac{6}{7}\), \(\frac{6}{7}\))</p>

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Forest

Forest

Condition of Forest in Nepal

Nepal is a small country but rich in biological diversity. It has 5400 vascular plants, including over 254 species of endemic plants and 700 species of medicinal plants. About 53.3% of the total land area of Nepal is covered by forest. Only 11% of the forest lies in Terai and Mountain and more than 50% of forest lies in Terai region. Many valuable tree species are growing in conservation areas, but scientific studies on their identification, validation, conservation and management are yet to be initiated. Forests provide 75% of the total energy consumed in the country (fuel wood) and more than 40% of fodder for livestock is extracted from forests.Needs and Importance of Forest

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Needs and Importance of Forest

Forest products are used in our daily lives. Forest offers watershed protection, timber and non-timber products, and various recreational options. They prevent soil erosion, help in maintaining the water cycle, and check global warming by using carbon dioxide in photosynthesis. When we cut the trees Its not just the trees but whole ecosystem falls apart. The forest provides oxygen which circulates in each and every living being. We cannot imagine our life without forest.

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Protected Plants

Harro, barro, bojo, sarpagandha, jatamasi (spikenard), panchaunle, yachagumba are protected medicinal herbs. These plants are protected by the government as they are in the verge of extinction. Many people are still doing illegal trading of those plants.

Lesson

Environment and its Balance

Subject

Science

Grade

Grade 8

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