Science
Joseph jogs from one end A to the other end B of a straight 300 m road in 2 minutes 30 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?
Motion in One Dimension
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Answer
(a) From A to B

Given,
Distance covered from A to B = 300 m
Time taken to travel from A to B = 2 min and 30 sec = 60 + 60 + 30 = 150 sec
Displacement from A to B = 300 m
Average speed =
Average velocity =
Substituting we get,
Average speed = = 2 ms-1
Average velocity = = 2 ms-1
Hence, average speed from A to B is 2 ms-1 and average velocity = 2 ms-1
(b) From A to C
Distance covered from A to C = 300 m + 100 m = 400 m
Time taken from A to C = 2 min 30 sec + 1 min = 60 + 60 + 30 + 60 = 210 sec
Displacement from A to C = 300 m – 100 m = 200 m
Average speed =
Average velocity =
Substituting we get,
Average speed = = 1.9 ms-1
Average velocity = = 0.952 ms-1
Hence, average speed from A to C is 1.9 ms-1 and average velocity = 0.952 ms-1
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