Ramesh went 15 m to the east, then he turned left and after \(5\sqrt 3 \) m turned 120° right and went \(10\sqrt 3 \) m and then turned 120° right and went \(20\sqrt 3 \) m. How far was Ramesh from the starting point ?
To determine how far Ramesh was from the starting point, we need to track his movements using coordinate geometry. We will break down his journey into segments, calculating his position after each turn and movement.
Ramesh's journey involves a series of movements in specific directions and then turns at certain angles. We can imagine his starting point as the origin (0, 0) on a 2D coordinate plane.
Understanding the direction after each turn is crucial for accurate coordinate calculation. We will use standard angles where East is 0°, North is 90°, West is 180°, and South is 270° (or -90°).
Let the starting point be \(O = (0, 0)\). We will calculate the coordinates after each segment of Ramesh's movement.
Ramesh started at point \(O = (0, 0)\) and ended at point \(D = (0, -10\sqrt{3})\). The distance from the starting point is the straight-line distance between O and D.
Using the distance formula: \(D = \sqrt{(x_2 - x_1)^2 + (y_2 - y_1)^2}\)
Here, \((x_1, y_1) = (0, 0)\) and \((x_2, y_2) = (0, -10\sqrt{3})\).
Distance \(OD = \sqrt{(0 - 0)^2 + (-10\sqrt{3} - 0)^2}\)
\(OD = \sqrt{(0)^2 + (-10\sqrt{3})^2}\)
\(OD = \sqrt{0 + (10^2 \cdot (\sqrt{3})^2)}\)
\(OD = \sqrt{100 \cdot 3}\)
\(OD = \sqrt{300}\)
To simplify \(\sqrt{300}\):
\(OD = \sqrt{100 \cdot 3} = \sqrt{100} \cdot \sqrt{3} = 10\sqrt{3}\) m
Therefore, Ramesh was \(10\sqrt{3}\) m from the starting point.
| Segment | Movement Description | Direction Angle (\(\theta\)) | Distance (d) | \(\Delta x = d \cos(\theta)\) | \(\Delta y = d \sin(\theta)\) | Current Position (x, y) |
|---|---|---|---|---|---|---|
| Start | (0, 0) | |||||
| 1 | 15 m East | \(0^\circ\) | 15 m | \(15 \cos(0^\circ) = 15\) | \(15 \sin(0^\circ) = 0\) | (15, 0) |
| 2 | \(5\sqrt{3}\) m Left (North) | \(90^\circ\) | \(5\sqrt{3}\) m | \(5\sqrt{3} \cos(90^\circ) = 0\) | \(5\sqrt{3} \sin(90^\circ) = 5\sqrt{3}\) | (15, \(5\sqrt{3}\)) |
| 3 | \(10\sqrt{3}\) m 120° Right | \(90^\circ - 120^\circ = -30^\circ\) | \(10\sqrt{3}\) m | \(10\sqrt{3} \cos(-30^\circ) = 15\) | \(10\sqrt{3} \sin(-30^\circ) = -5\sqrt{3}\) | (15+15, \(5\sqrt{3}-5\sqrt{3}\)) = (30, 0) |
| 4 | \(20\sqrt{3}\) m 120° Right | \(-30^\circ - 120^\circ = -150^\circ\) | \(20\sqrt{3}\) m | \(20\sqrt{3} \cos(-150^\circ) = -30\) | \(20\sqrt{3} \sin(-150^\circ) = -10\sqrt{3}\) | (30-30, \(0-10\sqrt{3}\)) = (0, \(-10\sqrt{3}\)) |
The final coordinates of Ramesh are \((0, -10\sqrt{3})\). The distance from the starting point \((0,0)\) is simply the magnitude of the y-coordinate, which is \(|-10\sqrt{3}| = 10\sqrt{3}\) m.
Some even numbers such as 6, 8, 24, 28, 32 and 46 are given. If you ask your students to sum any two even numbers given, then in each case they will get an even number. Therefore, by studying the various uses of this type, we can conclude that the sum of any two even numbers is always even. What kind of logic do we observe from the above statement?
I. Inductive reasoning
II. Deductive Reasoning
Match the following approaches of moral reasoning with their propounders:
| Moral Reasoning | Proponder(s) | ||
| (a) | Consequentialism Approach | (i) | Thomas Hobbes, Ayow Rand |
| (b) | Deontological Approach | (ii) | Aristotle |
| (c) | Natural law theory | (iii) | Ronald F. White |
| (d) | Theological Approach | (iv) | W.D. Ross, John Rawls |
Four words have been given, out of which three are alike in some manner and one is different. Select the one that is different.
Find the wrong number in the given series.
4, 8, 16, 24, 40, 62, 104, 168, 296
Select the missing number from the given responses.
| 5 | 6 | 3 | 8 |
| 9 | 6 | 8 | 7 |
| 7 | 4 | 5 | 6 |
| 51 | 38 | 29 | ? |