Question 2

Joseph jogs from one end A to the other end B of a straight 300 m road in 2 minutes 50 seconds and then turns around and jogs 100 m back to point C in another 1 minute. What are Joseph’s average speeds and velocities in jogging (a) from A to B and (b) from A to C?

Answer

(a) From end A to end B

Distance covered A to B = 300 m

Time taken to cover that distance = 2 min 30 seconds = 2 x 60 + 30 = 150 s

Average speed = 300 / 150 = 2 m/s

Average velocity = 300 / 150 = 2 m/s

The average speed and average velocity of Joseph from A to B are the same and equal to 2 m/s.

(b) From end A to end C

Total distance covered = Distance from A to B + Distance from B to C

= 300 + 100 = 400 m

Total time taken = Time taken to travel from A to B + Time taken to travel from B to C

= 150 + 60 = 210 s

Average speed = 400 / 210 = 1.90 m/s

Average velocity = 200 / 210 = 0.95 m/s

The average speed of Joseph from A to C is 1.90 m/s and his average velocity is 0.95 m/s.

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- NCERT Chapter

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