Two standard vehicles depart a warehouse at the same instant at a right angle. Their speeds are 45 km/h and 60 km/h. Find the direct distance separating them after 20 minutes. MCQ with Answer and Explanation
Two standard vehicles depart a warehouse at the same instant at a right angle. Their speeds are 45 km/h and 60 km/h. Find the direct distance separating them after 20 minutes.
A. 30 km
B. 20 km
C. 25 km
D. 35 km
Answer: Option C
Solution (By JKSSB Mock Tests)
Time = 20 minutes = 1/3 hours. Distance covered by first vehicle = 45 * (1/3) = 15 km. Distance covered by second vehicle = 60 * (1/3) = 20 km. Direct line distance = sqrt(15^2 + 20^2) = sqrt(225 + 400) = sqrt(625) = 25 km.
A thief escapes from police custody at 1:00 PM running at 45 km/h. The police discover the escape at 1:20 PM and start chasing him at 60 km/h. At what time will the police catch the thief?
A train 120 meters long running at 108 km/h completely passes another train 180 meters long running at 72 km/h in the same direction. How much time do they take to clear each other?
Explanation:
Total distance to be covered = 120 + 180 = 300 meters. Relative speed in same direction = 108 - 72 = 36 km/h = 36 * (5/18) = 10 m/s. Time taken = 300 / 10 = 30 seconds.
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