A partical moves in a straifgt line from `A` to `B` for the first `30 km` with speed `10 km//h` and the next `60 km` with speed `20 km//h`. Find the average speed and average velocity.

Explanation

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`A` to `C`: Time `t_(1)=30/10=3h`
`C` to `B`: Time `t_(2)=60/20=3h`
Total time `=t_(1)+t_(2)=3+3=6h`
Average speed`=(Total distance)/(Total time)=(30+60)/6=15 km//h`
Here, displacement =distance
Average velocity= Average speed `=15 km//h`