On a 60 km straight road, a bus travels the first 30km with a uniform speed of 30kmh^(-1). How fast must the bus travel the next 30 km so as to have average speed of 40kmh^(-1) for the entire tirp?

On a 60 km straight road, a bus travels the first 30km with a uniform

1.	On a 60 km straight road, a bus travels the first 30km with a uniform speed of 30kmh^(-1). How fast must the bus travel the next 30 km so as to have average speed of 40kmh^(-1) for the entire tirp?
Answer» SOLUTION :`V_(AVG)=(S_(1)+S_(2))/(t_(1)+t_(2))=(S+S)/(S((1)/(V_(1))+(1)/(V_(2))))=(2V_(1)V_(2))/(V_(1)+V_(2))` or `40=(2xx30xxV_(2))/(V_(1)+V_(2))impliesV_(2)=60kmh^(-1)`