Recent content by jangheej

why is evaporation rate (e.g. of water molecules) faster in the presence of the electric field? I understand that the water molecules become polarized and hence feel electric force... can anyone explain more specifically? thnx! =D *b.t.w. if you're interested in figure skating, please...

different surface area? why? the droplet is just resting on the surface (see the image below)

hi all =D i have a question about evaporation rate depending on curvature. say a droplet of water is placed on a curved surface- one concave, one convex but with the same radius of curvature. will the evaporation rate be different?

hi =) i'm doing an experiment on 2011 iypt problem Air Drying. -> "table utensils, after being washed, dry differently. Investigate how the drying time depends on relevant parameters." I've just begun on the experiment and have difficulty figuring out where to start! I'm thinking about...

Hi =) I have a question about tape peeling. An adhesive tape is sticked onto a surface. 1) You pull the tape off the surface 2) You drag the surface so that the tape is peeled off. (see the attachment) Will these two forces be the same? so... if I want to measure the force necessary to...

hi =D i observed something interesting during the experiment. i immersed a normal temperature wire in a chalet filled with water and particles (lycopodium, glitter) floating on the surface. the original problem is to immerse a "hot" wire (2011 IYPT problem) but i was curious what would...

hi all :) im trying to heat a metal wire in my experiment and because i don't have a heat sensor camera or an oven,... i thought of using a sand bath to control the heating temperature. is it possible to heat a wire upto 500~600 degree celcius by sand bath? (or whatever bath that may be...

hi all im studying polarization, and i want to check if i have the right idea about sky polarization. basically i want to find the position of the sun when i know the angle theta (refer to the attachment) of the sun but doesn't know the exact position. so i look at the portion of the sky...

confusing heat transfer... hi im really confused about the exact heat transfer mechanism of the phenomenon i observed the situations simple: if you immerse a red hot wire into water with small particles floating on the surface, the particles move really fast. at first, i thought it could...

but if the scale is what matters, then that means it doesn't matter which way you look at, doesn't it? assume that the sun is very large and far away and the line of sight is very short as you said - then that means regardless of which region of the sky you look at, the angle between the sun...

I learned that the light is 100% linearly polarized when one looks at the angle shown in pic1. But when taking a photo of a blue sky and also in polarization navigation, it says that we look at the direction of 90 angle from the sun ray cos it's the region of maximum polarization. (pic 2)...

peeling direction...? when I tried to peel a tape off the surface, I realized that it requires much larger force to pull in the direction shown in the left picture. Why is that? if we think about it, the adhesive force is caused by the adhesive filament that stretches and breaks as we apply...

hi all i'm a high school student doing a physics experiment about the peeling force of a tape. I want to see the realtionship between the peeling force and the peeling velocity but I cannot think of a good way to pull at constant speed. I tried to connect the spring to a motor so that the...

if you plunge a hot metal (like wire) into water, the water temperature obviously increases. I wonder what kind of heat transfer occurs between the metal and the water. it clearly doesn't seem like convection or radiation. But I am not so sure if conduction is the right one cos it is usually...

I'm trying to control the temperature of a wire/steel rod in my experiment. (of various size from a simple wire to a steel rod of diameter 5mm) In my preliminary experiment, I simply heated with alcohol lamp. But I'm not so sure which equation to use and if Q=cmT is the right equation, how I...