Question

While waiting to catch a commuter train, I was standing just inside the yellow safety line, about 1 meter from the platform edge. Little did I know that an Acela train was coming through without stopping. That train was moving at about 60 miles per hour (about 28 meters per second). Estimate the velocity in miles per hour that the wind from the train hit me, 10 seconds after the first car has passed. Suppose that I had stood back a safer distance, say 3 meters, from the platform edge. What would be the wind speed then? CARS 60 mph IM Hints: Assuming the train acts as a flat plate moving through air at 60 miles/hr, a boundary layer forms. You can calculate the distance the first car travels in 10 s. You can then check the Reynolds number to determine if the flow is laminar or turbulent, and using the appropriate equation, we can calculate the boundary layer thickness. Finally, using an expression for the velocity profile, you can then determine the velocity.

Answer 1

倒given Dala :: Acala hein 1am Bouncder is = 180m on hu veloci Scanned wit CamScanner

= 201 241 le s Cubic cs Scanned with CamScanner