Joseph jogs from one end A to the other end B of a straight 300 m road in 2 minute 30 second and then turns around and jogs 100 m back to point 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?

Explanation

(a) From A to B,
distance covered = 300 m = displacement,
time taken = 2 min 30 sec
`= 2 xx 60 + 30 = 150 sec `
Average speed `= ("Total distance covered")/("Total time taken")`
`= (300 m )/( 150 s ) = 2 ms ^(-1)`
Average velocity `= ("Displacement ")/("Time taken")`
`= (300 m)/(150)s ) = 2 ms ^(-1)`
(b) From A to B to C,
distance covered `= (300 + 100) m = 400 m`
displacemenet `= AB -BC = (300 -100) = 200 m`
time taken `= 2 min 30 sec + 1 min = (150 + 60) s = 210 s`
Average speed `= ("Total distance covered")/("Total time taken")`
`= (400)/(210) ~~ 1.90 ms ^(-1)`
Average velocity `= ("Displacement")/("Time taken") = (200 )/(210) ~~ 0.95 ms ^(-1)`
(a) Average speed `=1.90 ms ^(-1)`
Average velocity `= 0.95 m s ^(-1)`