As earth orbits the sun, different parts of earth receive more direct, concentrated
sunlight at different times of year. in this lab, you will demonstrate how the angle of the
sunlight affects its intensity.
materials
• colored pencils (green, blue, purple, orange, black)
• flashlight
• graph paper
• protractor
• ruler
• tape (masking and clear)
• textbooks (several)
procedure
flashlight setup (light source)
1. make a stack of textbooks about 6 inches high on a sturdy table.
2. lay the flashlight on its side on top of the stack of books, lining up the edge of
the flashlight so it is close to the edge of the stack. use masking tape to
secure the flashlight.
graph paper setup (the surface)
1. use clear tape to attach a sheet of graph paper to another textbook.
2. turn on the flashlight.
3. hold the book with the attached graph paper vertically in front of the
flashlight. move the graph paper closer or farther away from the flashlight,
until the light on the paper forms a medium-sized, sharp circle about 2–3
inches in diameter.
4. measure the distance from the edge of the graph paper to the flashlight and
record this number as “starting distance” below. make certain to keep the
graph paper at this starting distance throughout the experiment. turn off your
flashlight. caution: turn off the flashlight in between the steps of the
following experiment so the graph paper does not become too hot.
the experiment
1. have your learning coach (or someone else who is willing to assist you) hold
the graph paper vertically (straight up and down) at the starting distance in
front of the flashlight. 2. use a green colored pencil to draw around the outline of the light on the
graph paper. just draw around the most intense circle of light.
3. observe the brightness of the light inside this outline, and record your
observations below.
4. place the protractor next to the graph paper so that the 90º mark is lined up
with the vertical textbook. now tilt the textbook with the attached graph paper
10º.
5. use a blue colored pencil to draw around the outline of the light on the graph
paper. (remember, trace only the most intense area of light.)
6. observe the brightness of the light inside this outline, record your
observations, and compare the brightness of the light at this angle to the
previous outline.
7. repeat steps 4–6 for tilt angles of 20°, using a purple pencil, 30°, using an
orange pencil, and 40°, using a black pencil. record your observations
below.
analyzing your data
1. use the data table below to record the number of lighted squares.
2. count the approximate number of squares inside each light outline. record
your counts in the data table below. note: for partial squares, estimate how
much of the square is included. for example, if it looks like one-fourth of the
square is included, add 0.25 to your total. if it looks like half of the square is
included, add 0.5 to your total. (use decimals, not fractions.)
data table: number of lighted squares
degree of
tilt
0º
(green)
10º
(blue)
20º
(purple)
30º
(orange)
40º
(black)
number of
squares
within the
outline
(your group)
questions and conclusions
answer the questions below.
1. identify the independent variable in this experiment.
2. identify the dependent variable in this experiment.
3. identify two constants in this experiment. 4. how did the numbers of squares inside the outline change as the degree of
tilt increased?
5. how did the brightness or intensity of the light change as the degree of tilt
increased?
6. explain how this demonstration models the way in which the intensity of
sunlight shining on earth changes over the course of the year. be detailed in
your explanation.
7. which degree of tilt produced light similar to what north america experiences
in summer? explain your answer.
8. what would be the effect on the seasons and the northern and southern
hemispheres if earth were not tilted? explain your answer.
answer asap it's due tomorrow. i will rank brainliest.