OAT Practice 8 th Grade Science Science Inquiry & Scientific Ways of Knowing. Brought to you by:

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1 OAT Practice 8 th Grade Science Science Inquiry & Scientific Ways of Knowing Brought to you by:

2 Density Experiment The two graduated cylinders pictured can hold the same amount of water and use the same scale. A student measures the masses of two metal balls. One ball is made of aluminum and the other ball is made of lead. The student adds 50 ml of water to each graduated cylinder and then drops one metal ball into each graduated cylinder. 1) Which tool did the student use to measure the mass of each metal ball? A. Ruler B. Timer C. Balance D. Graduated cylinder

3 1) Which tool did the student use to measure the mass of each metal ball? A. Ruler If a student chooses A, he or she does not understand that a ruler is used to measure length and a balance is used to measure mass. B. Timer If a student chooses B, he or she does not understand that a timer is used to measure an amount of time and a balance is used to measure mass. C. Balance This is the correct answer. The students in this example used a balance to measure the mass of each metal ball. A balance needs to be used to find the mass of any object. D. Graduated cylinder If a student chooses D, he or she does not understand that a graduated cylinder is used to measure the volume of a liquid, and a balance is used to measure mass.

4 Density Experiment The two graduated cylinders pictured can hold the same amount of water and use the same scale. A student measures the masses of two metal balls. One ball is made of aluminum and the other ball is made of lead. The student adds 50 ml of water to each graduated cylinder and then drops one metal ball into each graduated cylinder. The student includes the sentence below in the write-up of this investigation. The lead ball has a measured mass of 113 grams. 2) Which kind of scientific statement is this sentence? A. Inference B. Prediction C. Explanation D. Observation

5 2.) Which kind of scientific statement is this sentence? A. Inference If a student chooses A, he or she does not understand that an inference is a conclusion based on an observation and/or an experiment. This statement is an observation that was made during the investigation. B. Prediction If a student chooses B, he or she confuses an observation with a prediction. A prediction is a stated expected outcome of a scientific investigation based upon scientific knowledge and/or evidence using a hypothesis (a proposed explanation for an observation or scientific problem). But the statement in this example is just an observation. C. Explanation If a student chooses C, he or she does not understand that the statement in this example is an observation and does not explain any of the data. D. Observation This is the correct answer. This sentence is an observation, which is a statement that notes or records a fact or something that has happened. Students need to know the difference between types of statements used in scientific investigations like observation and inference. Students reading about scientific investigations should figure out which statements only talk about facts and observations of an investigation and which statements make conclusions based on those facts and observations.

6 The weather information shown at the right was reported on Sunday, the 15th of the month, and two days later on Tuesday, the 17th of the month. The table includes conditions for Sunday only, whereas the maps report early morning conditions for both Sunday and Tuesday. Weather Table and Maps 3) According to the table of weather conditions, what was the average temperature in degrees Fahrenheit in Cleveland, Ohio, for the 24-hour period ending at 6 a.m. on Sunday? A. 53 degrees Fahrenheit B. 59 degrees Fahrenheit C. 61 degrees Fahrenheit D. 65 degrees Fahrenheit

7 3. According to the table of weather conditions, what was the average temperature in degrees Fahrenheit in Cleveland, Ohio, for the 24-hour period ending at 6 a.m. on Sunday? A. 53 degrees Fahrenheit If a student chooses A, he or she may not understand that the mean is the average of the high and low temperatures, not the low temperature. B. 59 degrees Fahrenheit This is the correct answer. The mean is figured out by adding the high and the low temperatures and dividing that answer by two. The high temperature was 65 and the low temperature was 53, so the mean is: ( )/2 = 59 degrees. C. 61 degrees Fahrenheit If a student chooses C, he or she may not understand that sixty one degrees Fahrenheit is a number between the high and the low temperatures, but it is not the mean temperature. D. 65 degrees Fahrenheit If a student chooses D, he or she may not understand that the mean is the average of the high and low temperatures, not the high temperature.

8 You live in Ohio and want to paint the outside of your house. You need fair weather for at least two days for two coats of paint to dry completely. 4) According to the weather maps, on which day should you start painting? A. Saturday, the 14th of the month B. Sunday, the 15th of the month C. Monday, the 16th of the month D. Thursday, the 19th of the month

9 You live in Ohio and want to paint the outside of your house. You need fair weather for at least two days for two coats of paint to dry completely. 4) According to the weather maps, on which day should you start painting? A. Saturday, the 14th of the month If a student chooses A, he or she may not understand that fair weather for painting will only come after the cold front leaves on Sunday. B. Sunday, the 15th of the month If a student chooses B, he or she may not understand that fair weather for painting will only come after the cold front leaves on Sunday. C. Monday, the 16th of the month This is the correct answer. The maps show that the cold front probably passed through Ohio sometime on or before Sunday and will be followed by a few days of clear weather. So, Monday the 16th is the best day to start painting. D. Thursday, the 19th of the month If a student chooses D, he or she may not understand that another cold front will come on Thursday, which will not bring fair weather for painting.

10 Ms. Williams science class uses a toy car race to study and collect data about forces and motion. The racetrack shown has a 6-meter ramp and a 5-meter level section to the finish line. Two cars compete at a time. The data table and graph below show the speed and total distance traveled for car 1 and car 2 during the first three seconds a race. 5) At what point on the track does a car reach its fastest speed? A. Halfway down the ramp B. At the bottom of the ramp C. Halfway down the level section D. At the finish line

11 5. At what point on the track does a car reach its fastest speed? A. Halfway down the ramp If a student chooses A, he or she may have thought that the car gets to its fastest speed when it is still moving down the ramp. But the car is still speeding up while it is on the ramp, as data in the table show. The car s speed is still increasing between 1.5 and 6 meters traveled on the ramp. B. At the bottom of the ramp This is the correct answer. Data in the table show that at 6 meters (the bottom of the ramp), the car is at its fastest speed of 6 meters per second. C. Halfway down the level section If a student chooses C, he or she may have thought that the car s speed is fastest after it is off the ramp and on the flat part of the track. But the car is slowing down when it is on the flat part of the ramp, as data in the table show. When the car is on the flat part, between 6 and 11 meters, its speed goes down from 6m/s to 4m/s. D. At the finish line If a student chooses D, he or she may have thought that the car does not get to its fastest speed until it gets to the finish line. But data in the table show that the car has slowed down to 4m/s by the time it gets to the finish line.