physics problem help

[spwath]

OK,I got everything, other than one question:

If a car is going at 15mph, how will it's air resistance compare when going 30mph? And 45mph?

Now I know it will be larger, but I could not tell the relationship.

[givingtnt]

nvm

[Tommy59375]

(ok, nevermind this post!)

[Stardar1]

will  be 4 times as much

 

equation for air resistance uses v^2, so v₁^2/v₂^2 gives the multiplier

[Benjio]

According to http://www.batesville.k12.in.us/physics/phynet/mechanics/newton2/air_resistance.htm Air resistance for larger objects (like a car) would be about proportional to the square of the velocity.

[as96]

OK,I got everything, other than one question:

If a car is going at 15mph, how will it's air resistance compare when going 30mph? And 45mph?

Now I know it will be larger, but I could not tell the relationship.

Just put "my car doesn't have gas in it so it can't even do 15mph" and you are going to be fine.

[spwath]

will be 4 times as much

equation for air resistance uses v^2, so v₁^2/v₂^2 gives the multiplier

That's what I was thinking

[Stardar1]

 

since the air density and object do not change, and the coefficient is a constant, it is only dependent on velocity

[spwath]

Is this literally the whole question, no table or anything? How many marks are available and what level are you working at?

Yes, based on the lab we did determining air resistance for coffee filters.

Marks?

Level is 11th grade honors physics

[spwath]

since the air density and object do not change, and the coefficient is a constant, it is only dependent on velocity

OK, that makes sense.

We just use that equation today for our lab, so I guess I could have applied it to this question (which is in the lab)