Independent Variable
How does the amount of water given to a lima bean seed affect how tall it grows?
Identify the Independent Variable
What is the amount of water?
How does the amount of water given to a lima bean seed affect how tall it grows?
Identify the Dependent Variable.
explains how a natural phenomenon works
What is a theory?
Maya designed an investigation to answer the following question: How does the amount of water given to a lima bean seed affect how tall it grows?
Maya’s Plan:
1. Place three lima beans in three different containers with the same amount of soil. Label the containers “A”, “B”, and “C”.
2. Place the containers on a windowsill will so they will receive the same amount of light.
3. Provide Container A with 1 ml of water each day, Container B with 5 ml of water each day, and Container C with 10 ml of water each day.
Observe, measure, and record growth every day.
Write a hypothesis for this investigation.
If lima beans need approximately one inch of water per week, then the lima bean in Container B may be most successful because Container A might not be enough, and Container C might be too much.
factors in an experiment that remain the same.
What is the constant or control?
How does the temperature of water affect the time it takes for a sugar cube to dissolve?
Identify the Independent Variable
How does the temperature of water affect the time it takes for a sugar cube to dissolve?
Identify the Dependent Variable
What is the time it takes for a sugar cube to dissolve?
describes a natural phenomenon or relationship that always occurs under specific conditions.
What is a law?
Anthony designed an investigation to answer the following question: How does the temperature of water affect the time it takes for a sugar cube to dissolve?
Anthony’s Plan:
1. Heat 200 ml of water using a hot plate. Remove from heat when the temperature reaches 50 degrees Celsius.
2. Measure 200 ml of room temperature water from the sink.
3. Set up 2 beakers, one with warm water and one with room temperature water.
4. Drop a sugar cube in each at the same time.
5. Start the timer and begin stirring.
6. Record how long it takes for each sugar cube to completely dissolve.
7. Repeat steps 1-6 two more times.
What is the purpose of Step 7? What is it called?
the factor measured or observed during an experiment
What is the dependent variable?
How does the surface of a ramp affect how far a toy car rolls?
Identify the Independent Variable.
How does the surface of a ramp affect how far a toy car rolls?
Identify the Dependent Variable
What is the distance the toy car rolls?
how or why something happens
Melika made a model to help understand why craters on the moon are different sizes. She represented the moon’s surface with a pan of flour. Melika represented objects that hit the moon with marbles. She thinks that dropping marbles from a greater height will make the crater’s diameter larger.
Melika’s Plan:
1. Fill a pan with flour and smooth out the flour.
2. Drop the marble from 10 cm above the pan and measure the diameter of the crater formed. Smooth out the flour.
3. Drop the marble from 20 cm above the pan and measure the diameter of the crater formed. Smooth out the flour.
4. Drop the marble from 30 cm above the pan and measure the diameter of the crater formed.
What could Melika do to increase the reliability of her results?
What is replication?
the factor that is changed by the investigator to observe how it affects a dependent variable
what is independent variable?
Which material is best for lima bean seeds to sprout?
Identify the Independent Variable.
What is the type of material?
Which material is best for lima bean seeds to sprout?
Identify the Dependent Variable
What is which lima bean sprouts best?
what happens everytime
What is a law?
Devon thinks wrapping a cotton towel around a jar of hot water will keep it warmer than without any wrapping at all. He is designing an investigation to determine whether construction paper, a paper towel, a cotton towel, or no wrapping at all will keep the water in the jar warmer.
Procedure:
1. Fill 4 jars with water that is 90°C.
2. Place a thermometer in each jar.
3. Wrap one jar with construction paper, one jar with a paper towel, and one jar with a cotton towel. Leave one jar unwrapped. Make sure the wrapped jars have equal thickness.
4. Record the temperature of the water in each jar after 15 minutes has passed.
Write a sample hypothesis based on what Devon thinks will happen.
Hypothesis: If cotton is considered an insulator, then the jars with cotton wrapped around it will maintain heat longer than the jars with paper or without because insulators will not let heat pass through easily.
a rule that describes a pattern in nature
What is scientific law?
Melika made a model to help understand why craters on the moon are different sizes. She represented the moon’s surface with a pan of flour. Melika represented objects that hit the moon with marbles. She thinks that dropping marbles from a greater height will make the crater’s diameter larger.
Identify the Independent Variable.
What is the height Melika drops the marble from?
Devon thinks wrapping a cotton towel around a jar of hot water will keep it warmer than without any wrapping at all. He is designing an investigation to determine whether construction paper, a paper towel, a cotton towel, or no wrapping at all will keep the water in the jar warmer.
Identify the Dependent Variable.
What is the temperature of jar after wrapping it vs. not wrapping?
supported by a large amount of empirical evidence
What is both a law and a theory?
Joseph designed an investigation to test the following question: Does the sun heat freshwater and saltwater at the same rate?
Procedure:
1. Dissolve 3 grams of salt in a beaker with 200 ml of water.
2. Pour 200 ml of water into a second beaker.
3. Place a thermometer in each beaker to make sure the temperatures of both the freshwater and saltwater are the same.
4. Place both beakers outside.
5. Every 5 minutes, record the temperature of the water in both beakers.
Write a hypothesis.
Hypothesis: If the conductivity and heat capacity of saltwater is higher than freshwater, then the saltwater should heat faster than freshwater because saltwater can hold more heat and transfer it more efficiently than freshwater.
an explanation of observations or events based on knowledge gained from many observations and investigations