Tuesday, April 2, 2013

ACT Science

SAT Question of the Day

The SAT question of the day is a Sentence Completion Question that has already been addressed on this blog: click here to see an explanation.

ACT Question of the Day

The ACT contains a science section that is not on the SAT.  However, you do not have to memorize science information to do well on this test!  All you have to do is be able to logically analyze and evaluate the information that you are given.  Even if you are only preparing for the SAT right now, take a look at this science question and consider whether your strengths are suited to the ACT.

Note:  ACT science passages throw a lot of information at you.  It is best to ignore the details in the charts until you know what information the question asks you to find.
Passage II
    The Sun's path from sunrise to sunset varies with the time of year. A student performed the following experiments on three clear, sunny days at three- or four-month intervals throughout the course of a year to study the path of the Sun through the sky.

Experiment 1
    At a chosen Northern Hemisphere location, the student placed a stick vertically into the ground so that 1 meter of its length was left above ground. The student knew that the length of the shadow was related to the height of the Sun above the horizon and that the shadow would point away from the direction of the Sun. The length in meters (m) and direction of the shadow cast by the stick were measured one hour after sunrise (Shadow A), at mid-morning (B), at noon (C), at mid-afternoon (D), and one hour before sunset (E) on each of the three days. The direction of each shadow was determined by placing a magnetic compass at the base of the stick and aligning the north arrow with the north mark on the compass. The direction of each shadow was then determined by a comparison with the compass face markings. The results are recorded in Table 1.

Table 1
Shadow
Day 1
Day 2
Day 3
Length
(m)
Shadow 
direction
Length 
(m)
Shadow 
direction
Length 
(m)
Shadow 
direction
A
5.0
SW
8.6
NW
6.8
W
B
1.2
W
2.9
NNW
1.7
NW
C
0.3
N
2.3
N
0.9
N
D
1.2
E
3.0
NNE
1.8
NE
E
5.0
SE
8.6
NE
6.9
E

Experiment 2
    The following year, the student repeated Experiment 1 at a chosen location in the Southern Hemisphere. The results are in Table 2.

Table 2
Shadow
Day 1
Day 2
Day 3
Length
(m)
Shadow 
direction
Length 
(m)
Shadow 
direction
Length 
(m)
Shadow 
direction
A
9.0
SW
5.0
NW
6.9
W
B
3.2
SSW
1.1
W
1.8
SW
C
2.5
S
0.3
S
1.0
S
D
3.2
SSE
1.1
E
1.8
SE
E
9.1
SE
5.0
NE
6.9
E

If the experiments were repeated after pounding the stick farther into the ground so that only 0.5 m was exposed, how would this affect the shadow lengths?

You are given a lot of information that you do not need to know to answer this question.  The passage tells you that the original stick had one meter exposed above the ground.  If you pound it in until .5 meters are exposed, you have taken half of the stick away.  Smaller things logically must make smaller shadows (think of a bug and a building at the same time of day), so look down at your answer choices.

A. They would be twice as long as those in the original experiments.
B. They would be one-and-one-half times as long as those in the original experiments.
C. They would be one-half as long as those in the original experiments.
D. They would be one-fourth as long as those in the original experiments.

(A)  The shadows would only get larger if more of the stick were exposed.  Eliminate this choice.
(B)  The shadows would only get larger if more of the stick were exposed.  Eliminate this choice.
(C)  This answer makes sense because if half of the original stick is showing, it must have half the shadow of the original stick as well.
(D)  Even if you carefully analyze all of the numbers in the chart, there are no important numbers that have a relationship of one-fourth.  Eliminate this choice.

The correct answer is (C).

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