When a vehicle passes through a road, it displaces air. Before the car passed through the road, this air was in equilibrium (assuming no wind), and hence any dust present in the area would have likely settled. When the vehicle passes through, this air is displaced and pushes the dust out of its "equilibrium" state. This is possible because dust particles have very little mass. If you consider: \(\vec{F} = m\vec{a}\)

\(\Rightarrow\) \(\vec{a} =\frac{ \vec{F}}{m}\)

Now, if the mass is extremely small (like that of a dust particle), then the magnitude of the acceleration will be much larger than that of say a rock, which has a much greater mass.

This is why dust blows when a car passes through a road.
–
Ethan Robinett
·
3 years, 1 month ago

Log in to reply

@Ethan Robinett
–
It will be best if you consider momentum,
Momentum of dust before = 0 ,
Momentum after = mv

Hence: Total Momentum : Momentum before = Momentum after

MV = mu + o
where M = Mass of Car and V is Velocity of car
–
Syed Baqir
·
2 years, 1 month ago

Log in to reply

It will be best if you consider momentum,
Momentum of dust before = 0 ,
Momentum after = mv

Hence: Total Momentum : Momentum before = Momentum after

MV = mu + o
where M = Mass of Car and V is Velocity of car
–
Syed Baqir
·
2 years, 1 month ago

Log in to reply

four words: rushing air from tires
–
Will-i-am Guo
·
2 years, 1 month ago

## Comments

Sort by:

TopNewestWhen a vehicle passes through a road, it displaces air. Before the car passed through the road, this air was in equilibrium (assuming no wind), and hence any dust present in the area would have likely settled. When the vehicle passes through, this air is displaced and pushes the dust out of its "equilibrium" state. This is possible because dust particles have very little mass. If you consider: \(\vec{F} = m\vec{a}\)

\(\Rightarrow\) \(\vec{a} =\frac{ \vec{F}}{m}\)

Now, if the mass is extremely small (like that of a dust particle), then the magnitude of the acceleration will be much larger than that of say a rock, which has a much greater mass.

This is why dust blows when a car passes through a road. – Ethan Robinett · 3 years, 1 month ago

Log in to reply

Hence: Total Momentum : Momentum before = Momentum after

MV = mu + o where M = Mass of Car and V is Velocity of car – Syed Baqir · 2 years, 1 month ago

Log in to reply

It will be best if you consider momentum, Momentum of dust before = 0 , Momentum after = mv

Hence: Total Momentum : Momentum before = Momentum after

MV = mu + o where M = Mass of Car and V is Velocity of car – Syed Baqir · 2 years, 1 month ago

Log in to reply

four words: rushing air from tires – Will-i-am Guo · 2 years, 1 month ago

Log in to reply