Question

A Ping-Pong ball hangs from a string that is attached to the rear view mirror of a parked car. The driver side window is open, and the passenger side window is closed. A strong breeze blows along the driver side of the car. What happens to the Ping-Pong ball? Assume the breeze is laminar and that Bernoulli’s equation applies. A Ping-Pong ball hangs from a string that is attached to the rear view mirror of a parked car (see A Ping-Pong ball hangs by a string from a car rearview mirror. The driver side window to the left of the mirror is open, while the passenger side window to the right of the mirror is closed.). The driver side window is open, and the passenger side window is closed. A strong breeze blows along the driver side of the car. What happens to the Ping-Pong ball? Assume the breeze is laminar and that Bernoulli’s equation applies.

a.The ball does not move in either direction.

b.The ball swings towards the passenger side.

c.The ball swings towards the driver side.

Answer 1

Whenever the air enters into the car through the window it pushes the ping pong ball towards the passenger's side and later gets reflected by the closed window and pushes the ball toward the drives side with more force. Therefore, the ball swings towards the driver's side.