Day 1 March 24 Came up with problem: How high does the dew point have to be to form dew on a glass? Wrote Hypothesis: If a glass is left outside , then dew will form because I know wetness forms on the glass mirror during a shower. I learned dew is the wet stuff that forms on plants in the morning. Day 2 March 26 I researched: found twelve note facts about dew points. I learned that “dew point” means the temperature at which dew forms.
Day 3 March 29 I wrote the rough draft of all my variables, procedure, and materials. I learned that I have to look on the computer to find the R.H. and the dew point for each day of my trials. Day 4 March 30 I finished my research on dew points and edited my hypothesis. Hypothesis: If a glass is left outside overnight, then dew will form in it at around a dew point of 62 F and a R.H. of 81 F (a 19 difference) because I know the dew point is not very far away or really close to the R.H. I learned the dew point is based off of the R.H.
Day 5 March 31 I wrote down the final draft of my variables, procedure, and materials. Day 6 April 6 I wrote down all my note facts on note cards. Day 7April 9,10,11 I tested my experiment of trial 1, 2, & 3 , and my hypothesis was correct!
Variables, Procedure, and Materials Problem: How high does the dew point have to be to form dew on glass? Hypothesis: If a glass is left outside , then dew will form at around 62 F with an R.H. of 81 (a 19 difference) because I know the dew point is not very far away or really close to the R.H. Materials: glass cup computer Independent Variable: I switch the days of my three trials based on the dew point of each day. Dependent Variable: The amount of dew on each glass changes and/or if there is or is not dew on the glass. Controlling Variable: The type of glass stays the same and where it is put outside all stays the same.
My Note Facts
Jake March 26, 2011 Dew Point Note Facts The dew point temperature is the temperature at which the air can no longer hold all of its water vapor, and some of the water vapor must condense into liquid water. The dew point is always lower than (or equal to) the air temperature. If the air temperature cools to the dew point or if the dew point rises to equal the air temperature, then dew, fog , or clouds begin to happen. http://www.weatherquestions.com/What_is_dewpoint_temperature.htm
The higher the dew point, the greater the amount of water vapor (invisible form of water) in the air. Water vapor gets into the air through evaporation. The warmer the air, the more water vapor it can hold. The dew point on a warm and humid day is high, in the 70s. On a dry and cool day, the dew point is very low, it can be freezing http://www.weatherworks.com/monthly/q_and_a/answer_dewpoint1.html
Continued The cold heat mixes with the hot heat creating condensation, basically the steam. This happens during a shower which fogs up your mirror. The definition of dew point is: "the temperature, at which dew begins to form." Dew is the water you find on your grass or car early in the morning. If the temperature reaches the dew point temperature, then dew will form. You measure the dew point by the temperature dew is supposed to form by prediction. “Relative humidity is the ratio of the amount of water vapor in the air at a given temperature to the maximum amount air can hold at the same temperature, expressed as a percentage” http://apollo.lsc.vsc.edu/classes/idm3020/tut_folder/nick_tutorial/#DPbasic
On a clear day, water evaporates from the warm ground into the atmosphere. When night happens, the ground sends the day’s warmth into the sky. The ground becomes much colder, causing the water vapor to squeeze. This squeezed (condensed) vapor is dew. http://www.pitara.com/discover/5wh/online.asp?story=9
The dew point is the point of temperature for dew to be able to form. How much dew that forms is caused by the relative humidity (R.H.) in the air. Relative humidity is how much moisture in the air. If there is a higher R.H. then more moisture.
Conclusion of Problem Dew can form on a glass left outside overnight, but in certain conditions. There had to be a clear night and morning. Also, the humidity had to be pretty high (around 84-100). Lastly, the temperature had to be around 0-5 close to the dew point. My hypothesis was correct!
Data of my Trials 6:00 A.M. Characteristics of Trials
April 9th after Trial Side view of glass Top view of glass
April 11th after Trial Side view of glass Top view of glass
April 12th after Trial Side view of glass Top view of glass
Credits How Does Dew Form?. Ajay Jaiman. 1998. Pitara Kids. 26 March 2011 < http://www.pitara.com/discover/5wh/online.asp?story=9> Temperature and Dew Point Tutorial . By Nickolas McColl. 26 March 2011 <http://apollo.lsc.vsc.edu/classes/idm3020/tut_folder/nick_tutorial/#Dpbasic> Answers to Weather Questions?????. Jennifer Nichols. 11/20/98. How the Weatherworks. 26 March 2011 <http://www.weatherworks.com/monthly/q_and_a/answer_dewpoint1.html> What is the dew point temperature?. 11/29/2010. WeatherQuestions.com. 26 March 2011 <http://www.weatherquestions.com/What_is_dewpoint_temperature.htm> Weather Underground. 4/9/2011. Houston KHOU. 9,11,12 April 2011 < http://www.wunderground.com/cgi-bin/findweather/getForecast?query=KHOU>