Question

A car travelling at `72 km//h` overtakes another car traveling at `54 km//h`. Assuming each car to be `5.0 m` long, find the time taken during overtake and the total road distance used for the overtake.

Answer 1

Car `A: v_(A)=72 km//h =72xx5/18=20 m//s`
Car `B: v_(B)=54 km//h =54xx5/18=15 m//s`
`v_(A//B)=v_(A)-v_(B)=20-15=5 m//s`
Now car `B` is at rest and car `A` is moving with a velocity of `5ms`.

Time taken during overtake `=(l_(A)+l_(B))/(v_(A//B))`
`=(5+5)/5=2s`
Total road distance : (Practically, both cars are in motion)

Road distance used `=5+d_(1)=5+v_(A)t`
`=5+20xx2=45m`