Experimental+Scenarios+Copy

Practice - Seed Germination and Radiation

A student investigated the effect of radiation on the germination of bean seeds. He thought that exposure to radiation would limit the seeds ability to germinate (grow) much like ultra-violet light causing skin cancer. Three hundred seeds were soaked in water for one hour. They were then divided into three groups of 100 beans each. One group was placed in a microwave * oven on high for three seconds. Another group was microwaved on high for six seconds. The last group was not microwaved. The seeds were then planted in three separate flats and given the same amount of water. The flats were placed in a location with a constant temperature of approximately 27 degrees Celsius. Each day for two weeks the number of seeds that germinated each group was recorded. The results of his experiment are noted below: *Note: microwaving the seeds exposes them to radiation
 * = Length of exposure ||= 3 seconds of radiation ||= 6 seconds of radiation ||= No radiation ||
 * = # Germinating seeds || 54 seeds ||= 26 seeds ||= 88 seeds ||

Complete each of the following:
 * 1) Identify the student's hypothesis:
 * 2) Identify the independent variable:
 * 3) Identify the dependent variable:
 * 4) Identify the other variables the student needs to consider/control during this experiment:
 * 5) Identify the control group in this experiment:
 * 6) Identify the experimental group:
 * 7) What conclusions might the student draw from this data?
 * 8) What recommendations might you suggest for further study or for improvement?

1-6 Maggie's Plant Experiment

Maggie read that some plants grow better if the soil is acidic. She can't believe that a plant can grow when exposed to acid. Maggie decides to test if the plants she has will grow better when acid is added to the soil. She puts potting soil in two planting containers and transplants two of her geraniums that seem about the same size into the pots. She puts the pots in the same location so that they both get the same sunlight each day, are at the same temperature and she makes sure they get the same amount of water. However, Maggie puts a tablespoon of vinegar * in the water she gives to one of the plants. She measures the growth of the plants every week for five weeks and records the results in a data the table below: *NOTE: Vinegar is a weak acid
 * = Week ||= Height of Plants with Vinegar (cm) ||= Height of Plants without Vinegar (cm) ||
 * = 1 ||= 10.0 ||= 10.0 ||
 * = 2 ||= 12.4 ||= 11.5 ||
 * = 3 ||= 14.8 ||= 13.0 ||
 * = 4 ||= 18.0 ||= 15.7 ||
 * = 5 ||= 21.4 ||= 17.8 ||

Complete each of the following:
 * 1) Identify Maggie's hypothesis:
 * 2) Identify the independent variable:
 * 3) Identify the dependent variable:
 * 4) Identify the other variables Maggie needs to consider/control during this experiment:
 * 5) Identify the control group in this experiment:
 * 6) Identify the experimental group:
 * 7) What conclusions might Maggie draw from this data?
 * 8) What recommendations might you suggest for further study or for improvement?

2-4 Donna's Pendulum Experiment

Donna has observed that her father can control the speed of their grandfather clock by adjusting the height of the weight on the end of the pendulum. Donna thinks that the pendulum will move faster when the weight is lowered, and wants to test her idea. //Donna gets a stopwatch and measures the time it takes for the pendulum to swing twenty times when the weight is moved to its lowest position//. Donna begins to move the weight up by 1 cm and continues to measure the time for twenty swings of the pendulum. Donna records her data:
 * Position ||= Time (seconds) ||
 * = 1 cm ||= 23.23 ||
 * = 2 cm ||= 21.56 ||
 * = 3 cm ||= 20.33 ||
 * = 4 cm ||= 19.00 ||
 * = 5 cm ||= 18.02 ||

Complete each of the following:
 * 1) Identify Donna's hypothesis:
 * 2) Identify the independent variable:
 * 3) Identify the dependent variable:
 * 4) Identify the other variables Donna needs to consider/control during this experiment:
 * 5) Identify the control group in this experiment:
 * 6) Identify the experimental group(s):
 * 7) What conclusions might Donna draw from this data?
 * 8) What recommendations might you suggest for further study or for improvement?

3-2 Al's Salt Water Experiment

Al wonders if adding salt to water will affect how long it takes the water to freeze. Al thinks that salt water will freeze more quickly than fresh water. He decides to check his hypothesis by conducting an experiment. Al takes two ice trays and fills one with distilled water and the other with distilled water that has two tablespoons of salt added. He makes sure he puts exactly the same amount of water in each ice tray. Al takes the trays and puts them side by side in the freezer. Al checks the ice trays every 10 minutes to see if the water in each tray has begun to freeze. Al finds that after 20 minutes the water in the ice tray without the salt has started to form ice while the ice tray with the salt water is completely liquid.

Complete each of the following:
 * 1) Identify Al's hypothesis:
 * 2) Identify the independent variable:
 * 3) Identify the dependent variable:
 * 4) Identify the other variables Al needs to consider/control during this experiment:
 * 5) Identify the control group in this experiment:
 * 6) Identify the experimental group:
 * 7) What conclusions might Al draw from this data?
 * 8) What recommendations might you suggest for further study or for improvement?

4-8 Christian's Cart Experiment

Christian wonders if a heavier cart will roll faster down-hill than a lighter one. He formulates a hypothesis and then decides to conduct an experiment. First, he finds a smooth ramp and a cart. He makes sure that the wheels of his cart roll freely. He set the ramp against a chair so one side of the ramp was 0.5 meters off the ground. Next, he measures the distance the cart will travel down the ramp. He leaves about 10 cm at the top of the ramp and draws a line to mark the release position of the car. He then measures the distance the cart will travel down the ramp and his stopwatch to time how long it will take to reach the bottom of the ramp. //He starts the experiment by measuring the time it takes the cart to roll down the hill without any weight on it.// For the next five trials he adds a 1 kg mass to the cart each trial. The times of the trials are as follows:
 * = weight (kg) ||= time (seconds ) ||
 * 1 || 27 ||
 * 2 || 32 ||
 * 3 || 30 ||
 * 4 || 29 ||
 * 5 || 30 ||

When comparing the data points, he decides to allow for a 5 second "fudge factor" since he may not have released the cart at precisely the exact same spot each time.

Complete each of the following:
 * 1) Identify Christian's hypothesis:
 * 2) Identify the independent variable:
 * 3) Identify the dependent variable:
 * 4) Identify the other variables Christian needs to consider/control during this experiment:
 * 5) Identify the control group in this experiment:
 * 6) Identify the experimental group(s):
 * 7) What conclusions might Christian draw from this data?
 * 8) What recommendations might you suggest for further study or for improvement?

5-7 Cattails

A scientist noticed that cattails grew only in swampy parts of his backyard. He decided to try to find out why. He went to the library and found out the following facts: cattails are not found in deserts, cattails are usually found in many swamps, cattails sometimes grow in rivers and streams. The scientist thought for while, then said "I think I have figured out the answer. Cattails need a lot of water to grow." He then went into his yard and dug up 100 cattails. He divided them into four groups. Each group contained 25 cattails. All of the groups were grown in the same type of soil, they all received the same amount of light, and they were all kept at the same temperature. There was only one difference between the groups. See the chart below to review the data:
 * = Group ||= 1 ||= 2 ||= 3 ||= 4 ||
 * = Water ||= 4 mL ||= 3 mL ||= 2 mL ||= 1 mL ||
 * = Average growth after 30 days ||= 8 cm ||= 4 cm ||= 2 cm ||= 1 cm ||

Complete each of the following:
 * 1) Identify the hypothesis:
 * 2) Identify the independent variable:
 * 3) Identify the dependent variable:
 * 4) Identify the other variables the scientist needs to consider/control during this experiment:
 * 5) Identify the control group in this experiment:
 * 6) Identify the experimental group(s):
 * 7) What conclusions might be drawn from this data?
 * 8) What recommendations might you suggest for further study or for improvement?

6 Candy Connection

Mr. Lehman wanted to know whether or not his students would do better on a quiz if he promised them candy. He went to the library and read several studies about the effect of giving food to lab animals. He found out that if animals were given food as a reward for doing something, they usually did better the more reward they were given. He guessed that the more candy that his students were promised, the better they would do on the quiz. He had all of his classes participate in the experiment. There were four groups. Each group had the same amount of boys and girls, they were all given the same quiz, they were all the same age, the same ability, and they were all from the same background. The first group was not promised any candy if they did well on the quiz. The second group was promised 1 candy bar if they did well on the quiz. The third groups was promised 2 candy bars if they did well on the quiz. The fourth group was promised 3 candy bars if they did well on the quiz. See the data table below for the results of this experiment:
 * = Group ||= # Promised Candy Bars ||= Test Average ||
 * = 1 ||= 0 ||= 70% ||
 * = 2 ||= 1 ||= 80% ||
 * = 3 ||= 2 ||= 90% ||
 * = 4 ||= 3 ||= 95% ||

Complete each of the following:
 * 1) Identify the hypothesis:
 * 2) Identify the independent variable:
 * 3) Identify the dependent variable:
 * 4) Identify the other variables Mr. Lehman needs to consider/control during this experiment:
 * 5) Identify the control group in this experiment:
 * 6) Identify the experimental group(s):
 * 7) What conclusions might be drawn from this data?
 * 8) What recommendations might you suggest for further study or for improvement?

7-5 Sunflower Seeds

Mr. Toowise was having a difficult time getting his students to get good grades on quizzes. He was trying to think of a way he could positively reward his students. He read an article that said that lab rats that were rewarded with sunflower seeds ran through a maze faster than rats that were not rewarded with sunflower seeds. Mr. Toowise stated, "I think that the more sunflower seeds I promise my students, the better they will do on a quiz." He divded the class into three groups. Group one was promised zero sunflower seeds if they did well on the quiz. Group two was promised 25 sunflower seeds if they did well on the next quiz. Group three was promised 50 sunflower seeds if they did well on the next quiz. The chart below summarizes the results from this experiment:
 * Group || # Sunflower Seeds Promised || Test Average ||
 * 1 || 0 || 70% ||
 * 2 || 25 || 73% ||
 * 3 || 50 || 71% ||

Complete each of the following:
 * 1) Identify the hypothesis:
 * 2) Identify the independent variable:
 * 3) Identify the dependent variable:
 * 4) Identify the other variables Mr. Toowise needs to consider/control during this experiment:
 * 5) Identify the control group in this experiment:
 * 6) Identify the experimental group(s):
 * 7) What conclusions might be drawn from this data?
 * 8) What recommendations might you suggest for further study or for improvement?

8-3 The Mice

A scientist observed that mice fed seeds appeared to grow more than mice fed leafy green and yellow vegetables. The scientist wondered if this might be caused by the higher concentration of protein in the seeds than in the vegetables. He decided to conduct an experiment to find out. The scientists got 200 mice of the same age, size, and gender and divided them into two groups of 100 mice each. He weighed each and fed Group A- a diet low in protein and Group B- the same food except he added a protein supplement. Both groups received the same amount of food each day. He checked the mass of each mouse each day and kept accurate records for 14 days. The results from his experiment are found in the data table below:
 * =  ||= Group A - diet low in protein ||= Group B - diet high in protein ||
 * = Average mass gained ||= 12 grams ||= 8 grams ||

Complete each of the following:
 * 1) Identify the hypothesis:
 * 2) Identify the independent variable:
 * 3) Identify the dependent variable:
 * 4) Identify the other variables the scientist needs to consider/control during this experiment:
 * 5) Identify the control group in this experiment:
 * 6) Identify the experimental group(s):
 * 7) What conclusions might be drawn from this data?
 * 8) What recommendations might you suggest for further study or for improvement?

9-1 Stinging Jellyfish

Jadyn and her family have a beach house in Galveston. Jadyn loves spending most of her summers there but always seems to get stung by jellyfish. This summer, she wants to have a good time without having to worry about the jellyfish. Jadyn wonders if jellyfish will sting her legs if she puts scented lotion on them. She believes the scented lotion will keep the jellyfish away buts wants to know for sure before she spends her allowance on expensive lotions.

Jadyn decides to conduct an experiment and recruits 16 of her friends to help out. She divides them into two groups of 8 each. One group spreads a scented lotion on their legs before going into the ocean while the second group does not use any lotion. The results of her study can be found in the data table below:
 * =  ||= Group 1 with Lotion ||= Group 2 without Lotion ||
 * = Stung ||= 1 ||= 7 ||
 * = Not Stung ||= 7 ||= 1 ||

Complete each of the following:
 * 1) Identify Jadyn's hypothesis:
 * 2) Identify the independent variable:
 * 3) Identify the dependent variable:
 * 4) Identify the other variables Jaydn needs to consider/control during this experiment:
 * 5) Identify the control group in this experiment:
 * 6) Identify the experimental group:
 * 7) What conclusions might Jadyn draw from this data?
 * 8) What recommendations might you suggest for further study or for improvement?