The webpage title could be: Calculating the Force of Air on Your Head

[Deeviant]

Ok I have the following question:

If the top of your head has a surface area of 113 cm2, what is the weight of the air above your head?

I'm not sure what I am doing wrong. I used the P = F/A. Solved for F to get F= P/A. I'm assuming the question is asking me for the force of the air on my head.

I'm using a figure of 1.013X10^5 Pa for atmospheric pressure, and I converted cm to meters then divide the P(101300 Pa) by A(1.13) meters, and webassign told me to go fish.

I'm sure I'm doing something wrong, just not sure what.

 

[Sirus]

Hmm. Try using kPa or keeping the area value in sq. cm. That might work.

 

[Deeviant]

Hmm well I did make one stupid mistake when solving for F, F= P*A. Although I still can't seem it get it right. I'm sure its something to do with units, I have been having huge problems getting the units right lately, sometimes they just don't make sense.

It wants the answer in N. So I would assume I have to convert cm to m since N is in meters. But I'm just not having any luck today with this question, the silly thing is this is the first question and I have answer most of the harder ones already, just can't get this one.

 

[Deeviant]

still need help..

 

[Leong]

1 m = 100 cm
$$(1\ m)^2 = (100\ cm)^2$$
$$1\ m^2= 1X10^{4}\ cm^2$$
$$113\ cm^2= \frac{113}{10^4} = 0.0113\ m^2$$
$$F=P*A=1.013X10^5*0.0113=1145\ N$$