Scientific Method
What are the two types of observation?
Qualitative Observations & Quantitative Observations
What are the two types of variables stated in a hypothesis?
Independent Variable & Dependent Variable
38.2 grams is equal to how many kilograms?
38.2 g = 0.0382 kg
0.72 meters equals how many centimeters?
0.72 m = 72 cm
This is the SI unit for temperature.
Kelvin
Blue, rough, metal are all examples of what type of observation?
Qualitative Observation
This variable is held the same throughout all aspects of the experiment, including both the control and experimental groups.
The constant variable!
Convert -235 °C to Kelvin.
TK = T°C + 273.15
TK = 38.15 K
Convert 4.3 days to seconds.
4.3 days x (24 hours /1 day) x (60 min/1 hour) x (60 sec/1 min)
371,520 seconds
Thinking about the following hypothesis: If soil temperatures rise, then plant growth will increase because plants like warmer climates.
What might a constant variable in this experiment be?
Using the same potting soil
Use the same type of plant
Both plants have the same amount of water
Both plants have the same amount of sunlight
What is wrong with this hypothesis?
If I put a plant in the closet, it will decrease its chance of living.
It's missing the "then" and because". It is also not specific enough and missing details.
Allison decides she wants to test which boils faster regular Coke or Diet Coke. She takes two pots one made of aluminum, another made from cast iron. She measures out 50 mL of regular coke and 50 mL of diet coke. She places both on the stove and turns one to medium heat and the other to medium high heat. Allison waits until the first one boils, turns off the stove. She does not collect any data.
Is this a controlled experiment?
No, because there are too many variables!
•Different types of metal pots
•One on medium, one on high heat
•Doesn’t wait for both to boil
•Doesn’t collect any data
If you have 2 gallons of water, what is this volume in cm3?
Conversions:
1 gal = 3.28 liters
1 L = 1000 cm3
2 gal x (3.28 L / 1 gal) x (1000 cm3 / 1 L)
6560 cm3
Convert 36 feet per second to feet per minute.
36 feet/sec x (60 sec/1 min)
= 2160 feet/min
Create a hypothesis for this experiment.
The soccer team is participating in a study that is analyzing how sports drinks affect performance on the field.
If the soccer team drinks sports drinks during the game, then they will be able to run faster and longer because sports drinks contain electrolytes.
If you drink more milk will you get stronger bones? State a good hypothesis for this question.
If you increase the amount of milk you drink, then you will increase the strength of your bones because milk contains a bone strengthening mineral called calcium.
Find the independent and dependent variables in the following experiment:
Alex wants to see how tall her daisies will grow with different amounts of fertilizers. She plants four daisies. One with no fertilizer and the other three with different amounts of the fertilizer.
IV: Amount of fertilizer on daisies
DV: Growth of daisies/height
Convert 22 °C to Fahrenheit.
T°F = (T°C x 9/5) + 32
T°F = 71.6 °F
Convert 86°F to Kelvin.
Step One:
T°C = (T°F - 32) × 5/9
T°C = (86 - 32) × 5/9
T°C = 30°C
Step Two:
TK = T°C + 273.15
TK = 30 + 273.15
TK = 303.15 K
You usually store your microwave popcorn in the kitchen cabinet, but you read an article that recommends storing it the refrigerator. You want to find out if microwave popcorn actually pops better if it is stored in the refrigerator. You have two bags of popcorn, so you keep one in the cabinet and place the other in the refrigerator. The next day, you pop each bag of popcorn for the same amount of time in the microwave. You measure the amount of popcorn that popped in each bag to see which bag produced more.
Which bag is the control group and which bag is the experimental group?
Control group: The popcorn bag that is stored in the cabinet.
Experimental group: The popcorn bag that is stored in the refrigerator.
Read the following experiment and write a good hypothesis.
I am doing a test to see if there is a connection between how long you run and how fast your heart beats. I will be performing an experiment where a person will run for 1 minute and I will check their heartbeat. Then they will run for 2 minutes and I will check their heart rate. I will do this up to 6 minutes and see if there is a connection.
If a person increases the amount of time they run, then their heartbeat will increase because their heart is working to pump out blood throughout the body.
Find the independent and dependent variables in the following experiment:
If you increase the number of times you practice shooting free-throws in basketball, then you will increase your chances of making a basket every time.
IV: number of times you practice shooting free-throws
DV: chances of making a basket
Your car tank can hold 16 gallons of gas. If you use 1 gallon per 25 miles, how many tanks would you need to fill to drive 2000 miles?
2000 miles x (1 gal/25 miles) x (1 tank/16 gal)
5 tanks
How many kilometers per hour are there in 240 meters per minute?
240 m/min x (1 km/1000 m) x (60 min/1 hour)
= 14.4 km/hour
Why is it necessary to have a controlled experiment in an experiment?
A controlled experiment means that only one variable is being tested. This is important because it means that you can directly see the relationship between the independent variable to the dependent variable in an experiment.