Joseph jogs from end A to the other B of a straight 300m road in 2min 30 sec and then turn around and jogs 100m 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 ?

Explanation

Total distance covered from AB = 300m
Total time taken `=2 xx 60 + 30s = 150s`
Therefore, Average speed
From AB = Total distance/Total Time

`=300//150 ms^(-1)`
`=2 ms^(-1)`
Therefore velocity from AB
=Displacement AB/Time =`300//150ms^(-1)`
`=2ms^(-1)`
Total Distance covered from AC = AB + BC
=300 + 200m
Total Distance covered from A to C + Time taken for AB + Time taken for BC
`=(2 xx 60 + 30) + 60s`
=210S
Therefore, Average speed from AC=
=Total distance/Total time
`=400//210 ms^(-1)`
`=1.904 ms^(-1)`
Displacement (s) from A to C = AB- BC
=300-100m = 200m
Time taken for displacement from AC = 210s
Therefore, velocity from AC = Displacement/Time
`=200//210 ms^(-1)`
`=0.952 ms^(-1)`