Physics Lab 1 Test - Quizzes From The Year

The length and width of a living room is 5.5 m and 4.8 m with an uncertainty of 0.1 m in each measurement. The perimeter of the room with associated uncertainty using either the "general method" or the "high/low method" presented in the pre-lab notes is: a. 20.6 ± 0.1 m b. 20.6 ± 0.6 m c. 20.6 ± 0.2 m d. 20.6 ± 0.4 m e. 20.6 ± 0.8 m

d. 20.6 ± 0.4 m

A large cylindrical spool of light string is attached to a wall. The radius is 0.3 m and the spool has a mass of 25 kg. A child pulls on the string with a force of 55 N and the spool begins to rotate. Determine its angular acceleration. 29.4 rad/s2 14.7 rad/s2 0.23 rad/s2 0.7 rad/s2 4.4 rad/s2

14.7 rad/s2

In the pre-lab notes for Lab 09, the differences between causal relationships and correlations were explored. In terms of the lab topic this week, the moment of inertia I, choose the best statement below for a single object of mass M. A causal relationship exists between the distribution of mass of an object and its moment of inertia (I). No correlation exists between the distribution of mass of an object and its moment of inertia (I). A negative correlation exists between the distribution of mass of the object and its moment of inertia (I). A positive correlation exists between the distribution of mass of the object and its moment of inertia (I). No relationship can be determined without actual data provided.

A causal relationship exists between the distribution of mass of an object and its moment of inertia (I).

Based on the plot shown, choose the mathematical model that best describes the relationship between the temperature of a steel beam and its length. Note that the origin shown on the graph is not (0,0). Assume that T is the temperature of the steel, L is the length of the beam, and α and β are constants that will be determined another way (i.e. fitting the data). a. L = αT + β b. L = αT c. L = αT 2 d. L = α/T

L = αT + β

Consider an ice skater spinning in place with both skates close together. At first she extends her arms out to both sides as she spins. Later, she brings her arms in close to her body. Which statement below is correct? The moment of inertia is larger when her arms are closer to her axis of rotation. The moment of inertia is larger when her arms are further from her axis of rotation. The moment of inertia of the skater is the same regardless of the position of her arms. The moment of inertia is smaller when her arms are further from the axis of rotation. More information is needed including knowing the actual mass of her arms.

The moment of inertia is larger when her arms are further from her axis of rotation.

dentify the control variables for the reported study. Choose from the following list: Daily diet (# of calories per day). Level of exercise (minutes per day). Participants had Type 2 diabetes. Participants were overweight. Participants were male.

a. 3 and 4 only.

A cylindrical gas bottle has a radius of 4.5 cm and a height of 30.0 cm. The uncertainty in both measurements is 0.1 cm. The directly calculated volume (V = π r2 h) of the bottle is 1908.5 cm3. Using the high/low method, which of the following is the best approximation to the uncertainty in this calculation? a. 4.5 cm3 b. 92 cm3 c. 0.00314 cm3 d. 0.1 cm3 e. 30 cm3

b. 92 cm3

Below is a plot of the time it takes to travel 100 miles for cars moving at different speeds. The graph has already been fitted with a power law curve with the form y = 100 x-1. Using new variable names of t for time and s for speed, which of the mathematical models below best fits this scenario? t = (100 miles) / s t = (100 miles/hr) / s s = (100 miles/hr) / t s = (100 miles) / t

t = (100 miles) / s

A student discovers that a photogate consistently reads 5% higher than expected, after all the data is collected. How should this error be handled? Each measurement can be reduced by the same amount (5%) in the first step of the data analysis. The manufacturer's calibration of 1% should be used for the uncertainty in the measurements and the student can ignore the fact that the readings are consistently 5% higher. Multiple readings should be taken and averaged to reduce the impact of this error. Knowing the size and direction of the systematic error is not enough to eliminate the effects of this error.

Each measurement can be reduced by the same amount (5%) in the first step of the data analysis.

A fitness store conducted a study and randomly chose 10 people to complete a survey regarding the number of months they owned a treadmill and the number of hours they spent exercising in the past week. The data is presented below. Note that it has been ordered from fewest to most months owned to make it easier to view the data. Negative correlation Positive correlation No relationship Causation More information is needed

Negative correlation

A group of students conduct an experiment to determine what factors impact the period of an oscillating spring-mass system. They choose 4 different springs of various stiffnesses which are listed in the data table from the most stiff (largest k) to the least stiff (smallest k). A causal relationship exists between the mass hung and the period because a change in mass caused a change in the period. No relationship can be determined as the students did not properly control all variables. A negative correlation exists between the mass hung and the period. A positive correlation exists between the mass hung and the period. No correlation exists between the mass hung and the period.

No relationship can be determined as the students did not properly control all variables.

Below is a plot that represents the relationship between the radius of a cylinder and its volume for a constant cylinder height of 10 cm. Which type of curve most likely fits the data? Use the summary table of common graphs provided at the end of pre-lab 03 for additional guidance, if needed. a. Linear Relationship b. Power relationship c. Power relationship d. Hyperbola

Power Relationship (y=Cx^p,p>1)

A group of students are provided with three objects all of the same mass and radius. The objects include a solid cylinder, a thin hoop (or cylindrical shell), and a solid sphere. The students are asked to predict which will get to the bottom of a ramp first if all three are released together from the same distance up the ramp. Which prediction is correct if the objects are listed in order from fastest to slowest? Hoop (fastest), sphere, cylinder (slowest). Cylinder (fastest), sphere, hoop (slowest). Hoop (fastest), cylinder, sphere (slowest). Cylinder (fastest), hoop, sphere (slowest). No relationship can be predicted with the provided information. Sphere (fastest), cylinder, hoop (slowest). Sphere (fastest), hoop, cylinder (slowest).

Sphere (fastest), cylinder, hoop (slowest).

The engine in a small airplane is specified to have a torque of 60 N•m. This engine drives a 2.0 m long, 40 kg propeller. How can you model this in terms of moments of inertia? The airplane can be modeled as a rotating cylinder about one end. The propeller can be modeled as a rod that rotates about its center. The propeller can be modeled as a rotating cylinder. The propeller can be modeled as a rod that rotates about one end. The engine can be modeled as rotating drum.

The propeller can be modeled as a rod that rotates about its center.

Using the data collected by two groups shown in the figure below, what is the best statement that you can make about the value of the object's true mass? The true value cannot be known. More data is needed to make a claim regarding the true value. The true value of the mass is in the intersection of the measurements by the groups The true value is somewhere between the minimum and maximum mass values of the combined dataset.

The true value cannot be known.

Consider a group of students who conduct the same projectile lab you completed for Lab 04. They find the uncertainty of their calculated trajectory range and, following standard laboratory practices, assumed that this is one standard deviation σ. They use this value to draw the bands on their target. After their initial launch, they record a number of additional launches to verify their estimate of σ. Of the following choices, what is the best interpretation if after 40 launches the group's carbon paper looked like the following? (The middle blue line is the prediction, the outer lines indicate the range of uncertainty.) There is a systematic error here. The uncertainty was overestimated. The uncertainty was underestimated. The uncertainty was estimated correctly

The uncertainty was overestimated.

As in the previous question, what is the best interpretation if the following pattern appears on the bottom colored paper? The uncertainty was overestimated. There is a systematic error. The uncertainty was estimated correctly. The uncertainty was underestimated.

There is a systematic error.

Consider measuring the period of a pendulum with a stopwatch. Suppose that the stopwatch is running slow. Which one of the following statements is correct? This will lead to underestimation of all of our time results. Systematic errors, unlike random errors, shift the results in one direction. This will not change our estimation because all of our time results will be nearly the same. We would just need to consider random error, not systematic error. This will vary our results in both the positive and negative direction, allowing for a varied estimation. We would need to average these errors to obtain our true systematic error This will lead to overestimation of most of our time results. Systematic errors, unlike random errors, always shift the results in the positive direction.

This will lead to underestimation of all of our time results. Systematic errors, unlike random errors, shift the results in one direction.

You must read the New York Times article "Diabetes Study Ends Early With a Surprising Result" found in the pre-lab notes before answering the pre-lab quiz questions this week.The hypothesis for the study presented in this article is: a. Diet and exercise impact risk of heart attacks, strokes, and cardiovascular deaths in diabetics. b. Diet and exercise impact blood sugar levels, blood pressure, and cholesterol levels in diabetics. c. Diet and exercise impacts likelihood of becoming diabetic. d. Diabetes impacts likelihood of developing heart disease.

a. Diet and exercise impact risk of heart attacks, strokes, and cardiovascular deaths in diabetics.

Over a period of 10 days a student measures the average growth of three similar plants grown in three different lighting conditions: A, B, C. a. DV = lighting conditions; IV = number of days b. DV = plant growth; IV = lighting conditions c. DV = lighting conditions; IV = plant growth d. DV = number of days; IV = lighting conditions e. DV = number of days; IV = plant growth

b. DV = plant growth; IV = lighting conditions

Two students want to determine if the mass of water changes during heating. Both start with about 40 g of water and heat their water samples the same way for the same length of time. After heating they each measure the mass of their own samples again using the same electronic balance as before (note that each student uses an electronic balance with a different uncertainty). Consider the data gathered by each student in the table below. a. Both students may claim the mass of the water changed during heating. b. Student 1: The mass of the water changed during heating.Student 2: Considering my experimental range of uncertainty, the mass of the water did not change during heating. c. Student 1: Considering my experimental range of uncertainty, the mass of the water did not change during heating.Student 2: The mass of the water changed during heating. d. Both students may claim the mass of the water did not change during heating.

b. Student 1: The mass of the water changed during heating.Student 2: Considering my experimental range of uncertainty, the mass of the water did not change during heating.

A student measures the mass of a solution before and after a chemical reaction takes place. In both cases the students measures the mass to be 50.25 g on an electronic balance with an uncertainty of 0.05 g. The student realizes that the ranges of uncertainty for each measurement overlap exactly. Which claim can the student make? We can't know for sure whether or not the mass changed, but it seems reasonable to claim that the mass did not change, given that the ranges of uncertainty overlap. The mass definitely stayed the same because the measurement of 50.25 g was obtained each time. The mass definitely stayed the same because the ranges of uncertainty overlap exactly. Both b and c are correct claims the student can make.

?

Much has been reported in the media about the relationship between SAT scores and a test-taker's family income. Consider the graph below concerning SAT Math Scores and family income as reported in The New York Times on August 27, 2009. A positive correlation exists between SAT test score and family income. A negative correlation exists between SAT test score and family income. No correlation exists between the SAT test score and family income. A causal relationship exists between the SAT test score and family income because a change in family income caused a change in the SAT score. A causal relationship exists between the SAT test score and family income because a change in the SAT test score caused a change in family income.

A positive correlation exists between SAT test score and family income.

A group of students perform an experiment and obtain a result of 53 ± 3 meters for some measured distance. They compare their measurement to the theoretical value of 57 meters (which has no associated uncertainty). What claim can they make using the equivalency criterion procedure that was introduced in lab 02 and will be used throughout in this lab course? At the 95% confidence level, the range of uncertainty for the measured values is from 47 m to 59 m. This includes the theoretical value so the results are consistent with the theory. The range of uncertainty for the measured values is from 50 m to 56 m. This does not include the theoretical value so the results are not consistent with the theory. At the 95% confidence level, the range of uncertainty does not include the theoretical value so the results are not consistent with the theory. The range of uncertainty for the measured values is from 48.8 m to 57.2 m. This includes the theoretical value so the results are consistent with the theory.

At the 95% confidence level, the range of uncertainty for the measured values is from 47 m to 59 m. This includes the theoretical value so the results are consistent with the theory.

A group of students conduct an experiment to determine how a change in mass hung on a spring in a constant gravity situation impacts the amount it stretches. They select one spring and collect the data as shown below. They are excited to see that their collected data supports Hooke's Law (F=-kx) as presented in their textbook. What claim can the students make about the relationship between the mass hung and the amount of spring stretch assuming the spring constant (k) is held constant? A causal relationship exists between the mass hung and the amount of spring stretch because a change in mass caused a change in the amount of spring stretch. No relationship can be determined as the students did not properly control all variables. A negative correlation exists between the mass hung and the amount of spring stretch. A positive correlation exists between the mass hung and the amount of spring stretch. No correlation exists between the mass hung and the amount of spring stretch.

A causal relationship exists between the mass hung and the amount of spring stretch because a change in mass caused a change in the amount of spring stretch.

A researcher, Tom, uses a measuring tape to collect data each day for one week to see how fast a tomato plant grows. Tom also asks his two daughters, Elizabeth and Janice, to see how tall the plant is each day as well, using the same measuring tape. After reviewing the height data below, determine which daughter has more uncertainty associated with the measurements as compared with Tom's measurements. The measurements of both daughters are so inconsistent that it suggests there is a problem with the measuring tape. Janice has more uncertainty associated with her measurements because her technique is in question; she did not consistently measure to the nearest hundredth centimeter. Both daughters have about the same amount of uncertainty as they are within 0.9 cm of each other and their dad, which is reasonable for a measuring tape. Elizabeth has more uncertainty associated with her measurements because her discrepancies with Tom's daily heights are the same or much more than Janice's.

Elizabeth has more uncertainty associated with her measurements because her discrepancies with Tom's daily heights are the same or much more than Janice's.

A student measures the temperature of a solution before and after a chemical reaction takes place. In both cases the student finds the temperature to be 25.2 °C, using the same thermometer with an uncertainty of 0.1 °C. Which claim made by the student below is correct? I can't say for sure if the temperature changed or not because there is a range of uncertainty with each measurement. Because the ranges of uncertainty overlap, however, it is reasonable to make the claim that the temperature did not change. b. The temperature changed. The ranges of uncertainty indicate the temperature before and after the reaction could be anywhere within these ranges therefore the temperature must have changed. c. I can say with 100% certainty that the temperature stayed the same because the range of uncertainties overlap exactly. d. The temperature did not change because both measurements have the same uncertainty of 0.1 °C

a. I can't say for sure if the temperature changed or not because there is a range of uncertainty with each measurement. Because the ranges of uncertainty overlap, however, it is reasonable to make the claim that the temperature did not change.

Two students collect data from grocery stores located in twelve different cities for the price per pound of apples, plums, and oranges. They compute the average price for each as well as the standard deviation for the data set they collected. What conclusion may be drawn about the price of apples, plums, and oranges using the graph below and employing the equivalency criterion? The cost of oranges and the cost of apples are similar in some grocery stores due to the overlapping error bars shown, but plums cost less per pound. The cost per pound of these three common fruits are similar due to the error bars shown. The costs of these three common fruits differ from each other, with oranges being the most expensive per pound and plums the least expensive. A conclusion cannot be made using this data since each average price has an uncertainty associated with it.

The cost of oranges and the cost of apples are similar in some grocery stores due to the overlapping error bars shown, but plums cost less per pound.

One hundred samples of several different plant parts were placed in each of six sealed containers of equal volume. The amount of CO2 present in the containers at the beginning was 250 mL. After 2 days, it was at the level shown in the table. Suppose the researcher hypothesizes that the amount of CO2 absorption is related to the type of plant. If she selects container 5 as one of her containers, what conditions should she choose for a new container 6 to test her hypothesis? a. Myrtle leaf, orange light, 27°C b. Myrtle leaf, orange light, 21°C c. Myrtle root, red light, 21°C d. Oak leaf, orange light, 27°C e. Oak root, red light, 21°C

a. Myrtle leaf, orange light, 27°C

The results of the study (choose one): a. Refuted the hypothesis. b. Not enough information was presented in the article to answer this question. c. Supported the hypothesis. d. Were determined by the researchers to be inconclusive.

a. Refuted the hypothesis.

A group of students conducted an experiment to determine what impacts the rate mold grows on bread. They decided to test whether or not preservatives in the bread made a difference in addition to the temperature in which the bread was stored. They purchased 2 loaves of bread that contain preservatives and 2 loaves that did not. They placed 5 pieces of each type of bread in 6 different environments of various temperatures ranging from 40°F to 85°F. The students were careful that each environment was basically identical except for temperature. After collecting data over 3 weeks the students made the claim that bread containing preservatives has a slower rate of mold growth when compared to bread without preservatives. They also made the claim that storing bread at lower temperatures reduces the rate of mold growth. Consider the following statements made by each student as they discuss what assumptions need to be discussed in their lab reports:Sam: In our report we need to write that we assumed that the two loaves of preservative-free bread were from the same batch and therefore identical to one another in terms of ingredients and age. We also need to write that we assumed the two loaves of bread with preservatives were identical in terms of ingredients and age. Alex: I agree with Sam but we should take it one step further and include a statement that we assumed that all four loaves of bread were actually of the same age and freshness as well. Troy: I agree with both of you, but we also need to include a statement that we assumed that our method of measuring the area of mold growth on each piece of bread was the most accurate. a. I agree most with Alex's statement. b. I find all three statements severely lacking. c. I agree most with Sam's statement. d. I agree most with Troy's statement.

a. I agree most with Alex's statement.

On the first page of New York Times article in the pre-lab, the researchers claimed that "for every hour of television watched after age 25 it shortens the viewer's life expectancy by 21.8 minutes". Consider the arguments of the students below who are evaluating the strength of the claim based on what they believe to be limitations of the study design: Student 1:I am not sure I believe the claim. The study design involved surveys of real people and asked about general health, disease status, exercise, smoking, diet, and number of hours of TV watched each week. This data should have been discussed as a limitation of the study because people are not good judges about these types of things.Student 2:I am not sure I believe the claim. I agree with student 1, but we should also question how the study participants were recruited. Maybe the people who were surveyed do not represent the broader population. This should have been discussed by the authors as another limitation of the study.Student 3:The claim is believable. The sample size used in the study is 12,000 adults. That is large enough to minimize any of the limitations of the study suggested by the other two students and therefore did not need to be discussed by the authors. a. Student 1 b. Student 2 c. Student 3

b. Student 2

Consider the following scenario: According to Sustainable Enterprises, coffee grounds can greatly benefit plants. They allow for a slow release of nitrogen and they can also increase nitrogen balance. Nitrogen helps plants use carbohydrates to gain energy. Nitrogen controls how plants take their form and how they function inside, and nitrogen helps plants make proteins that help them grow strong and healthy. Coffee grounds have been shown to increase the growth of plants because they have been said to release important nutrients used by the plants. According to Grow Joe, coffee grounds also release magnesium and zinc, micronutrients and amino acids. Without enough magnesium, plants may have brown/yellow older leaves. The coffee grounds can also feed earthworms; they loosen the soil; they retain water; and they release caffeine which repels slugs.Based on this information, students hypothesized that adding coffee grounds to the soil would affect the growth of Brassica rapa plants as measured by their leaf mass (size of leaves grown). They tested this by adding different amounts of coffee grounds to pots of soil before transplanting Brassica rapa seedlings into the pots. These amounts included 0, ¼, ½, ¾, and 1 cup of coffee grounds in each pot. Consider the following assumption made by the students:"The Brassica rapa seedlings transplanted into each pot were similar in health." a. This is not an appropriate assumption because the health of the plant cannot be checked. b. This is an appropriate assumption because the health of the plant might impact leaf growth. c. More information needs to be included in this particular assumption before a determination of its appropriateness can be made.

b. This is an appropriate assumption because the health of the plant might impact leaf growth.

Identify the independent (IV) and dependent (DV) variables for the reported study. a. IV = blood sugar levels, blood pressure, and cholesterol levels; DV = level of diet and exercise. b. IV = rate of heart attacks, strokes, and cardiovascular deaths; DV = level of diet and exercise. c. IV = level of diet and exercise; DV = rate of heart attacks, strokes, and cardiovascular deaths. d. IV = level of diet and exercise; DV = blood sugar levels, blood pressure, and cholesterol levels. e. IV = level of diet and exercise; DV = likelihood of becoming diabetic. f. IV = likelihood of becoming diabetic; DV = level of diet and exercise.

c. IV = level of diet and exercise; DV = rate of heart attacks, strokes, and cardiovascular deaths.

When discussing assumptions in lab reports for this course, which of the following is the best course of action that you should take? a. List the assumptions in your Lab Records; nothing else needs to be done. b. List the assumptions and state how they changed the experiment. c. List the assumptions, state exactly how they may affect the results, and suggest what could be done to improve the experiment if it were to be repeated. d. Change your results to align with your assumptions, because they are what are known.

c. List the assumptions, state exactly how they may affect the results, and suggest what could be done to improve the experiment if it were to be repeated.

A scientist is trying to increase the number of cells grown in the lab. After giving 3 different treatments, she obtained the results presented in the table below. Percent survival of cell cultures Cell Type Treatment A Treatment B Treatment C HeLa* 79% 25% 54% Stem 56% 18% 81% Kidney 18% 9% 2% T cells 22% 22% 22% *HeLa cells come from an immortal human cancer cell line. They were taken from a patient, Ms. Henrietta Lacks, in 1951 and have been continuously grown for research to this day. Ms. Lacks' cells have been credited with helping find a cure for polio as well as becoming an effective model to study (and hopefully cure) cancer. What one of the following represents possible dependent and independent variables for the investigation in this scenario?

c. DV = percent survival of cell cultures; IV = treatment

In a previous lab you applied several mathematical models to determine where a ball projected horizontally off a table will land. The resulting equation for determining where the ball will land (R) is given in the box below. Note that in the equation vx represents the horizontal velocity of the ball as it leaves the table, h is the height of the table, and g is the acceleration due to gravity. What type of relationship between height of table (h) and range (R) is represented in this equation? Choose the best statement below. a. A negative correlation exists between range (R) and height of table (h). b. No correlation exists between the range (R) and height of table (h). c. A causal relationship exists between the range (R) and height of table (h). d. A causal relationship exists between the range (R) and height of table (h) if the horizontal velocity (vx) and acceleration due to gravity is held constant. e. Both c and d.

d. A causal relationship exists between the range (R) and height of table (h) if the horizontal velocity (vx) and acceleration due to gravity is held constant.

Consider this graph which shows carbon dioxide levels that were measured each January over five decades at the Mauna Loa observatory in Hawaii. What is a possible hypothesis for the investigation portrayed in this scenario? a. The amount of atmospheric carbon dioxide is increasing each year. b. All investigations measuring the amount of atmospheric carbon dioxide would yield similar results. c. If the levels of atmospheric carbon dioxide were measured in another observatory at the same latitude the same results would be found. d. The amount of atmospheric carbon dioxide is related to the year it was measured. e. The amount of atmospheric carbon dioxide is related to the location it was measured.

d. The amount of atmospheric carbon dioxide is related to the year it was measured.

The graph represents the amount of product created in a reaction aided by one of two enzymes. [Enzyme A is represented by the line mostly on top and Enzyme B is represented by the line with the sharper peak.]What is a possible hypothesis for the investigation portrayed in this scenario? a. Enzyme B creates more product at a reaction temperature of 45 °C than Enzyme A. b. The enzyme used is related to the temperature of the reaction. c. The temperature of the reaction is related to the amount of product created. d. Enzyme A creates more product than Enzyme B for most temperatures. e. The amount of product created is related to the temperature of the reaction.

e. The amount of product created is related to the temperature of the reaction.

Imagine a study designed to investigate the study of postmenopausal hormones (hormone replacement therapy or HRT) on the risk of breast cancer. The researchers plan to track two cohorts of women over 5 years and compare instances of breast cancer of postmenopausal age women who take HRT with those who do not. What limitation(s) to the study design should be considered by the researchers when they begin to write up their findings? Those taking HRT would be more likely to have mammograms and therefore more likely to be diagnosed with breast cancer than those who do not. This would lead to an overestimate of the relationship between HRT and breast cancer. b. Any imbalances between the two cohorts of other factors that have a known connection to breast cancer, such as smoking or family medical history. c. Sample size of each cohort d. a and b e. a, b, and c f. None of the above

e. a, b, and c