Physics: Bernoulli’s principle with pressure and velocity (multiple choice)

Question

Driving slowly down a two-lane highway a large transport truck passes me going the same way as I am. As he does physics flashes before my eyes, and I think Bernoulli’s principle with pressure and velocity. Would I be pushed closer to the truck, or pushed away from it?

 

a. Pushed closer

b. Pushed away

Answer 1

Hi, 

 

You'll definitely understand the answer to this question once we breakdown Bernoulli's Principle. We can define it in the following way. 

 

1) The speed and pressure of the flowing fluid (which means either a liquid or gas) are inversely proportional a.k.a.  if the velocity of the fluid increases then its pressure automatically decreases. 

 

In the situation you gave, you're driving slowly in one lane (say, the right lane) while a truck (obviously travelling faster than you) passes you in the left lane. As the truck whooshes besides you, it speeds up the air between it and your vehicle. Since this air now has a higher speed, it also has a lower pressure, especially when compared to the air on the other side of you. So think of it this way: when the air pressure between you and the truck is less than the air pressure between you and the open environment - what will result? This area of higher pressure will push you towards the truck. Does that make sense?

 

Please feel free contact me if you have any more questions or need any more clarification!