Student Packet for the Golf Ball Experiment:
Question: Why do objects sink or float? How can we make an object that sinks in water, float?
Hypothesis: If we increase the density of a liquid by changing the concentration of matter in it, we can make a heavy object float.
Variables: (We will discuss this portion later, once the experiment is complete)
Vocabulary:
Matter:
Density:
Dissolve:
Solution:
Solute:
Solvent:
Solubility:
Solute:
Materials:
Jar of Salt, plastic wrap, Glass Jar, Graduated Cylinder, Golf Ball, Measuring Spoon, Long Mixing Spoon, Triple Beam Balance, Calculator, Paper & Pencil, Water, Food Coloring, Centimeter Ruler
Procedures:
1.) Place the jar’s lid upside down on the triple beam balance. Find the mass of your jar’s lid. Record the measurement in grams on your Measurements Chart.
2.) Place the golf ball in upside down lid so it will not roll off of the balance. Find the mass of both items and record your data on your Measurements Chart. Remove both the lid and golf ball from the balance.
3.) Fill a graduated cylinder with water to the last measurement – 50mL. (REMEMBER: a liquid will form a parabola when it is placed in a cylinder. This is because liquids have surface tension and the molecules will stick to the side of the cylinder. To record the measurement in a graduated cylinder, you must read the measurement at the BOTTOM of the curve or parabola.) Pour the water into the jar. Continue to fill and record the amount of water in milliliters (mL) until your glass jar is ¾ of the way full. Record the measurement in milliliters (mL) on your Measurements Chart.
4.) Use a Centimeter Ruler and record the water level in the jar by placing the ruler against the side of the jar, and measure from the bottom edge up to the water level. Record your information on the Measurements Chart.
5.) Drop the golf ball into the jar.
6.) Use the Centimeter Ruler and record the new water level in the jar by placing the ruler against the side of the jar, and measure from the bottom edge up to the water level. Record your NEW information on the Measurements Chart. **(REMEMBER: This change in measurement can be used to find the density of an irregular shaped object. You will need this later for one of your charts!)**
7.) Put plastic wrap over your balance tray. Using the tablespoon (Tbl.) measurement, place 1 tablespoon of salt on the triple beam balance and find the mass. Record your measurement in grams on your paper. Remove plastic wrap from balance and pour salt back into salt jar.
8.) Use the attached data chart to record number of tablespoons of salt and your observations throughout the rest of this experiment.
9.) Add ONE tablespoon of salt to the ¾ filled water jar at a time. Stir the salt water UNTIL water appears clear. Record your measurement of salt and your observation of what happens to the WATER and the GOLF BALL when a new tablespoon as added to the jar.
10.) Repeat step 9 until the golf ball floats.
11.) Fill your graduated cylinder with 50 mL of FRESH WATER. GRADUALLY add water to your jar (ONLY 10 mL at a time) until you observe a change with the golf ball. RECORD the amount of water that was used on your paper.
12.) Call your teacher over to add a few drops of food coloring. – DO NOT SHAKE THE JAR! (GENTLY SIR THE TOP SURFACE OF THE WATER AND FOOD COLORING UNTIL IT IS EVENLY DISTRIBUTED.)
Height of Jar
(Water Level):
Use a ruler and measure the tall side of the jar, from the bottom to the top of your water level:
Multiply the length of the jar by the width of the jar by the height of the jar:
Multiply: Salt measurement on balance by the number of tablespoons used to make golf ball float.
Divide the mass of salt by the volume of the water.
This is the height of the liquid used in your jar to help find the Volume of your liquid.
This will tell you the total volume of the liquid used in this experiment.
The total amount of salt added to the water in the jar.
The amount of matter added to the water to make the golf ball float
Volume of Jar with Liquid:
V = L x W x H
Mass of Salt:
Mass X # of Tbl. Sp.
Density of Salt Solution:
Mass ÷ Volume of water
Variables:
Control:
Dependent:
Independent:
Data Analysis:
(These are suggestions for what you might want to include in your analysis section.)
a.) Summarize what you did in the experiment
b.) Write down other observations you made during the experiment.
c.) Write about similarities or differences you fond in your data
d.) Write about what you learned from the data.
e.) Provide and talk about all variables used in the experiment.
f.) Make predictions as to why you go your results in the experiment.
Conclusion:
a.) Restate the hypothesis. (Rewrite the SAME hypothesis you used in the experiment and at the beginning of you lab report.)
b.) Tell if you findings supported/did not support the hypothesis and WHY.
c.) Did anything go wrong in the experiment? What could you have done differently?
d.) EXPLAIN what you learned in the experiment and how it is related to what we are studying in class