A person drives a car at a constant speed of 90 km/h along astraight line from point A to point B and then drivesback along the line from B to A at a constant speed 110 km/h. What is her average speed over the entire trip? How do I findthe average speed when this question has no information about thedistance? A person drives a car at a constant speed of 90 km/h along astraight line from point A to point B and then drivesback along the line from B to A at a constant speed 110 km/h. What is her average speed over the entire trip? How do I findthe average speed when this question has no information about thedistance?
Explanation / Answer
Given V = 90 km / h V' = 110 km/ h Average speed V " = 2VV' / ( V + V ' ) = 99 km / h