A sound wave travels at a speed of 330 m/s. If the echo of a sound is heard from a wall after 2 seconds, find the distance of the wall from the source. MCQ with Answer and Explanation
A sound wave travels at a speed of 330 m/s. If the echo of a sound is heard from a wall after 2 seconds, find the distance of the wall from the source.
A. 600 meters
B. 660 meters
C. 300 meters
D. 330 meters
Answer: Option D
Solution (By JKSSB Mock Tests)
Total distance traveled by the sound wave to the wall and back = Speed * Time = 330 * 2 = 660 meters. Distance to the wall = 660 / 2 = 330 meters.
A man can walk a distance in 4 hours and ride back in 3 hours. If he walks both ways, he takes 8 hours. How much time will he take if he rides both ways?
Explanation:
Let walking time one way be W and riding time one way be R. W + R = 7 hours. Walking both ways: 2W = 8 => W = 4 hours. Substituting W in first equation: 4 + R = 7 => R = 3 hours. Riding both ways: 2R = 2 * 3 = 6 hours.
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