Science Challenge


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    The bullets in the bottom corner of each problem indicate the question has not been answered. Questions left unanswered will be given a value of nr(no response).

    1) If the sun is approximately 93,000,000 miles away from the earth, and light travels at 186,000 miles/second, to the nearest tenth of a minute, how long does it take a ray of light from the sun to reach the earth?

    Your answer must be rounded off to the nearest tenth of a minute!


    2) A plane flies due north at 500 miles/hour. A wind blows from the west at 100 miles/hour. To the nearest tenth of a mile/hour, what is the resultant speed of the plane? Your answer must be rounded off to the nearest tenth !


    Need help?
    Read about Vectors

    3) A red blood cell has a size of .00000075 meters. How would this be expressed in scientific notation

    A) 75 x 10 -8 meters
    B) 75 x 10 -7 meters
    C) 7.5 x 10 -7 meters
    D) .75 x 10 -6 meters


    Need help?
    Read about Scientific Notation
    The following graph shows the phase transition for water.

    Phase Transition for Water

    4) Where will liquid water be found during this transition?

    A) only in b
    B) only in c
    C) c and d
    D) b,c and d
    E) only d


    5) What state of matter is water at letter e?

    A) solid
    B) liquid
    C) gas
    D) plasma

    Need help?
    Read about States of Matter

    6) - 10) A student designs an experiment to measure the time it takes for a ball to roll down an inclined plane that is 100 cm. in length. The student records the data for distance, d(cm.) and time, t (sec.) in a table and then plots the points on a graph as shown below.

    t (sec.)
    0 0

    6) In this experiment, what is the independent variable?

    A) distance
    B) time
    C) velocity
    D) acceleration


    7) What is the dependent variable?

    A) distance
    B) time
    C) velocity
    D) acceleration

    8) What would be a constant variable in this experiment ?

    A) velocity of the moving ball
    B) angle of inclined plane
    C) time
    D) distance


    9) What would be the best-fit for the points shown in the graph above?

    A) a best-fit straight line
    B) connecting the points with lines
    C) a best-fit non-linear curve
    D) none of the above

    10) Which of the following statements best explains the data from this experiment?

    A) The velocity of the ball is independent of the height of the inclined plane.
    B) The velocity of the ball increases over time as it moves down the inclined plane.
    C) The ball rolls down the inclined plane at a constant velocity.
    D) Their is a direct relationship between the velocity of the ball down the incline and the height of the incline.

    11) An experiment was designed to study the effects of soil temperature on the growth of tomato seedlings. Which step in the scientific method would the following statement occur? "...After five days we observed three sprouts from five of the twenty seedlings that were planted..."

    A) results
    B) conclusions
    C) hypothesis
    D) procedure


    12) Units of measure are a critical part of describing every measurement. There are seven base units of measurements. Length, mass and time are three of them. Other units are called derived quantities. Examples of derived units are: area (square-meters) and density (kilograms/cubic meter).

    Given that:

    a (acceleration) = v (velocity) x t (time)
    F (Force) = m (mass) x a (acceleration)
    W(Work) = F(force) x d (distance)

    Using the table of equations shown above, what are the derived units of measure of work?

    A) kg -m2/sec2
    B) kg-m//sec 2
    C) m/s2
    D) m/ kg-s2

    Need help?
    Read about Units

    13) In a certain species of plants the color red (R) is dominant to the color white (r). Using the Punnett Square, find the probability of an offspring being red if one parent is (RR) and the other is (Rr).

    Parent (Rr)
      R r
    R RR Rr
    R RR Rr
    Parent (RR)


    A) 50%
    B) 25%
    C) 75%
    D) 100%

    14) What is the proper method to focus a microscope while viewing a slide?

    A) Start with the lowest power objective and move the lens down until the image is in focus.
    B) Start with the highest power objective lens down as close to the slide without touching the slide. Then focus up.
    C) Bring lowest power objective lens down as close to the slide without touch the slide. Then focus up away from the slide.
    D) Start with the lowest objective lens 1 inch above the slide and then focus down till the image is in focus.


    15) Below are microscope images of two different types of plant cells. The cell walls of both types of cells are clearly visible. Chloroplasts are only visible in the algae not in onion skin. What is the most plausible reason for this?

    A) Plagiomnium affine (fish tank algae) B) Onion Skin with Iodine Stain

    A) Chloroplasts in onion plant cells are too small to be seen with the microscope.
    B) Since onion bulbs grow below ground they do not get the light necessary for chloroplast development.
    C) The chloroplasts are not visible in the onion skin because the iodine stain bleached the green color.
    D) The microscope is out of focus so we are not able to clearly see the chloroplasts in the onion skin.


    16- 17) On earth, a spring scale reads 100g with an unknown mass shown in blue. The balance beam on the right requires 100g. to balance the scale on earth.

    16) What would happen on the moon if the same experiment was performed?

    A) On the moon, the spring scale would read 100g. The balance scale would need 100 g. to balance the beam.
    B) On the moon, 100 g would be needed to balance the beam but the spring scale would read 0 g.
    C) On the moon, the spring scale would read around 16.6 g and the balance beam would need 0 g
    D) On the moon, the spring scale would read around 16.6 g and the balance beam would need 100g.

    17) What is the spring scale on the left measuring?

    A) weight
    B) mass
    C) density
    D) the spring constant


    Need help?
    Read about Mass vs. Weight


    18) A bar with a black box mass of 200 kg is shown on the left side of the balance scale pictured below. Use the information in the diagram to answer questions 18-21


    18) This is an example of what type of simple machine?

    A) wedge 
    B) inclined plane
    C) lever
    D) screw

    19) What is point A is called?

    A) effort
    B) fulcrum
    C) resistance
    D) load

    Need help?

    20) What is the unkown mass needed to balance the bar?



    Need help?


    21) What is the mechanical advantage of this simple machine?

    Need help?


    22-23) The graphs below show the annual mean carbon dioxide growth rates for Mauna Loa from 1960-2010 (left graph) and the global-mean surface temperatures from 1880-2007 (right graph).

    22) During which time span is the greatest change in temperature found?

    A) 1880-1920
    B) 1920-1940
    C) 1940-1970
    D) 1970-present


    23) Analyzing the two graphs above leads one to conclude that

    A) increase in atmospheric CO2 is an ocean phenomena.
    B) increase in atmospheric CO2 does not correlate well with increase in temperature.
    C) global warming may be a result of increased CO2 in the atmosphere.
    D) annual mean temperature should start to decline soon.

    Formaldehyde CH2O

    Formaldehyde, a common molecule found throughout the solar system, is composed of carbon, hydrogen and oxygen. It's used on Earth for preserving and embalming biological specimens.There is recent evidence that it may be the molecule responsible for the origin of life on Earth.

    Which is the correct Lewis dot diagram for formaldehyde?



    25) If both diamond and graphite are made of only carbon atoms, then why is diamond hard while graphite is soft? Use the molecule images shown below to help in your answer.


    A) Diamond has a crystal structure similar to ice.
    B) The carbon atoms found in diamond are different than the carbon atoms in graphite.
    C) The carbon-carbon bonds in graphite are all single bonds.
    D) Diamond has a rigid network of carbon atoms that cannot move.

    Need help?
    Read about Graphite and Diamond


    Did you check the right side bullets to make sure all questions have been answered? All bullets should be clear.

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