Sharad starts from Point Y and drives 9 km towards the South. He then takes a left turn, drives 19 km, turns right and drives 23 km. He then takes a right turn and drives 8 km. He takes a right turn and drives 17 km. He then turns left, drives 11 km, turns left and drives 6 km to stop at Point Z. How far (shortest distance) and towards which direction should he drive in order to reach Point Y again? (All turns are 90 degrees turns only unless specified)
21 km towards the north
This problem involves tracking a series of movements in different directions to find the final displacement. We need to determine the shortest distance and direction from the final point (Point Z) back to the starting point (Point Y).
Let's track Sharad's position step-by-step. We can use a coordinate system where Point Y is the origin (0, 0). We'll consider North as the positive y-axis, South as the negative y-axis, East as the positive x-axis, and West as the negative x-axis.
| Step | Direction of Movement | Distance (km) | Change in X | Change in Y | Position (X, Y) | Current Facing Direction |
| Start | - | - | 0 | 0 | (0, 0) (Point Y) | - |
| 1 | South | 9 | 0 | -9 | (0, -9) | South |
| 2 | East (Left Turn) | 19 | +19 | 0 | (19, -9) | East |
| 3 | South (Right Turn) | 23 | 0 | -23 | (19, -32) | South |
| 4 | West (Right Turn) | 8 | -8 | 0 | (11, -32) | West |
| 5 | North (Right Turn) | 17 | 0 | +17 | (11, -15) | North |
| 6 | West (Left Turn) | 11 | -11 | 0 | (0, -15) | West |
| 7 | South (Left Turn) | 6 | 0 | -6 | (0, -21) (Point Z) | South |
The final position is Point Z at coordinates (0, -21). The starting position was Point Y at (0, 0).
To return from Point Z to Point Y, we need to calculate the required change in coordinates:
A displacement of \(+21\) km in the y-direction means moving 21 km towards the North.
The journey back from Point Z to Point Y requires a net movement of 0 km horizontally (East-West) and 21 km vertically (North).
The shortest distance is calculated using the Pythagorean theorem, based on the net displacements:
Shortest Distance \(= \sqrt{(\Delta x)^2 + (\Delta y)^2}\)
Shortest Distance \(= \sqrt{(0 \text{ km})^2 + (21 \text{ km})^2}\)
Shortest Distance \(= \sqrt{0 + 441 \text{ km}^2}\)
Shortest Distance \(= \sqrt{441 \text{ km}^2}\)
Shortest Distance \(= 21 \text{ km}\)
The direction associated with the net displacement of +21 km in the y-axis is North.
Therefore, to reach Point Y again from Point Z, Sharad should drive 21 km towards the North.
A man starts from ‘O’, travels 20 km towards East to reach point ‘A’, turns right and travels 10 km to reach point ‘B’, turns right and travels 9 km to reach point ‘C’, turns right and travels 5 km to reach point ‘D’, turns left and travels 11 km and stops for some time and travels 1 km to reach point ‘E’ and then turns right and travels 6 km to reach point ‘F’.
What is the shortest distance between point ‘A’ and point ‘D’?
In the morning X and Y are walking towards each other in a park. When they meet, Y's shadow' falls upon X. In which direction was X facing?
Two workers K and L start walking from the same point. K walks 5 km North, then turns right and walks 2 km. Meanwhile, L walks 3 km West, then turns South and walks 4 km. Finally L turns left and walks 5 km. Where is K with respect to L?