Question

name nikkaya scott date sep 10, 2023 block: blue 4
scientific method and density review

1. a science team is trying to determine whether adding a particular particle type to sandy soil will help it retain water. in the study, the team will treat one group with the particles and the control group will be sandy soil (treated with particular particles? likely typo, intended: without particles) kept in a tray with small holes in the bottom. as water is added to the tray at a known rate, the rate of water passing through the holes will be measured. what property should the control group have?

a it should include the same soil type without the particles added.
b it should include the same soil type with the particles added.
c humus should be added to it to help it to retain water.
d water should be added to it at a lower rate

1. coral bleaching causes coral colonies to become white in color. the chart shows several factors related to coral bleaching. how should the various factors in the chart be used in an experiment to test their effects on coral?

a as constants
b as controls
c as responding variables
d as manipulated variables
chart (partially visible): \to coral bleaching\ with factors: excess shade, sudden water temperature changes, storm water runoff, inorganic nutrients, excess sediment

1. energy from the wind is used to turn windmills. these windmills then spin a generator and produce electricity. a scientist wants to determine the best placement for a windmill on her property. she places 50 windmills all over the property 50 yards apart and takes daily recordings of wind speeds for six months. which would most likely make the results of the investigation more reliable?

a taking the observations at the same time each day
b having only one person collecting the data
c checking the local forecasts to verify results
d making notes on weather conditions

1. xavier is conducting an investigation on erosion. he plans to use identical stream tables of varying slopes. xavier will fill each table with the same amount of sand. he will also pour four gallons of water down each table. which most likely explains the purpose of xavier changing the slope of the stream tables?

a to test the results of manipulated variables
b to control the dependent variables
c to determine how the dependent variables influence the outcome of the investigation
d to determine how the independent variable influences the outcome of the investigation.

1. the chart below shows the change in world installed wind power capacity between 1996 and 2008. wind power capacity is the amount of energy produced by wind turbines to generate electricity. according to the graph, which of the following is true about world installed wind power capacity?

a wind power capacity more than tripled between 2004 and 2008
b wind power capacity had increased 80,000 megawatts by 2006
c wind power capacity rose most quickly between 2006 and 2008 (corrected: \post\ → \most\)
d wind power capacity was close to zero until the year 2000
bar graph: \world installed wind power capacity\ with years 1996, 1998, 2000, 2002, 2004, 2006, 2008 and capacity (megawatts) on y - axis

Explanation:

Question 1

The control group should have the same conditions as the experimental group except for the variable being tested (the particle type). So it should have the same soil type (sandy soil) without the particle added. Option A is wrong (different soil), C is adding a different substance, D is about rate not control group setup.

In an experiment, constants are factors kept the same. The factors like "Excess shade", "Sudden water runoff" etc., if used as constants, are kept unchanged to isolate the effect of the independent variable (coral bleaching cause being tested). They aren't responding (dependent) or manipulated (independent) here.

Making notes on weather conditions (like wind direction, precipitation) helps account for other factors that could affect wind speed and windmill performance. Taking at same time (A) is good but not as impactful for reliability as noting confounding variables. Having one person (B) doesn't add reliability. Checking forecasts (C) isn't about the investigation's data reliability.

Answer:

B

Question 2