Final answer:
The direct distance from Point M after 2 hours can be calculated using trigonometry and vector components based on the truck's northward, eastward, and N 30°W travels at a speed of 85 kph, and applying the Pythagorean theorem.
Step-by-step explanation:
The question involves calculating the shortest direct distance from the starting point, Point M, after the truck has traveled in three different directions at a constant speed of 85 kph. To solve this, we'll need to use the concepts of vectors and trigonometry.
First Leg: The truck travels northward for 30 minutes, which is 0.5 hours. At 85 kph, the distance covered in this leg is 0.5 hours × 85 kph = 42.5 km north.
Second Leg: Next, the truck travels eastward for one hour. Distance covered = 1 hour × 85 kph = 85 km east.
Third Leg: The truck then shifts to N 30°W and continues for another 0.5 hours (since the total travel time is 2 hours). To find the distance in this leg, we must first find the northward and westward components using sine and cosine:
- Northward: 85 kph × cos(30°) × 0.5 hours
- Westward: 85 kph × sin(30°) × 0.5 hours
Finally, we calculate the total northward and eastward components and use the Pythagorean theorem to find the direct distance from Point M:
- Total northward: 42.5 km + (85 × cos(30°) × 0.5)
- Total eastward: 85 km - (85 × sin(30°) × 0.5)
Apply Pythagorean theorem: √(Total northward² + Total eastward²)
The calculated value will be the direct distance from Point M after 2 hours.