best working model for btech 1st year student

best working model of physics for 1st year b tech

Abstract

The objective: I set out to answer the following question: Which new roofing material, proposed to meet the requirements of recent California legislation, reflects the most light and reaches the lowest maximum temperature? I predicted that a white roofing material would reflect the most light and reach the lowest maximum temperature.
Methods/Materials

My materials included: a light meter, a heat lamp with 2 bulbs, 2 thermometers, 2 plastic storage boxes, 6 roofing samples including: white bitumen, black bitumen, granule bitumen, white plastic, black plastic, and tan plastic. To carry out my experiment I built and wired a heat lamp, placed one roofing sample beneath each bulb of the heat lamp, and recorded both sample's maximum temperature after 45 minutes using a standard barbecue thermometer. Each sample was tested beneath each side of the heat lamp for precision. I also visited a camera shop and used a light meter to measure the light reflected off of each material compared to a gray sample which had a reading of 7.0. To find which color of roofing material reflected the most light and reached the lowest maximum temperature, I tested different colors and two different types of materials.

Results

My experiments showed that white plastic roofing material changed least in temperature with a change of 28ºF, followed by tan plastic(37ºF) and white bitumen(38ºF). Of the two kinds of white material, the white plastic's maximum temperature was lower while the white bitumen reflected a little more light. The white bitumen reflected the most light in the light meter test with an average reading of 9.1.

Conclusions/Discussion

My experiments showed that overall, white plastic roofing reached the lowest maximum temperature while white bitumen reflected the most light. Although I predicted white to reach a lowest maximum temperature and to reflect the most light, this experiment allows me to see that an alternative colored roofing material can be used and have the same effects as a white material. This is shown in the tan plastic's temperature change of 37ºF compared to the white bitumen's temperature change of 38ºF. I find these measurements interesting, because they show an alternative, perhaps more aesthetically appealing and cleaner looking roofing choice for consumers that does not have the same negative environmental effects as a darker roofing material.

The project tested the maximum temperature and light reflectance of roofing materials that have been proposed to meet the requirements of recent California legislation.