s8pe-104cr-ca
12/20/05
7:27 PM
MAZER
Page 126
Thinking Critically
Use the information in the photograph below
to answer the next three questions.
30. INFER Cooking oil floats on water. What can
you infer about the density of cooking oil? (8.8.d)
31. COMMUNICATE Concrete blocks help anchor
a pier. Use a drawing to help explain why it
would be easier to move these blocks when
they are under water than when they are
on the shore. (8.8.c)
Using Math Skills in Science
Complete the following calculations.
50 mL
58 mL
23. INFER One way to find the volume of a marble
is by displacement. To determine a marble’s
volume, add 50 mL of water to a graduated
cylinder. Then, place the marble in the
graduated cylinder. Why does the water level
change when you add the marble?
32. What is the volume of an aquarium that is
120 cm long, 60 cm wide, and 100 cm high?
33. You have three pennies. The total mass of
the pennies is 6.6 grams and the total volume
of the pennies is 0.74 cubic centimeters.
Find the density of the pennies. (8.8.b)
34. A piece of balsa has a volume of 30 cm3 and
a mass of 3.6 g. What is the density of
balsa? (8.8.b)
24. CALCULATE What is the volume of the marble?
(8.8.a)
25. PREDICT If you carefully removed the marble
and let all of the water on it drip back into the
graduated cylinder, what would the volume of
the water be? Explain.
26. COMMUNICATE You have a glass of ice water.
You push an ice cube under the surface of the
water. Explain what happens to the ice cube,
referring to Archimedes’ principle. (8.8.c)
27. INTERPRET You have a stick of butter that you
cut up into small pieces. How does the density
of the original stick of butter compare with the
density of the smallest piece? Explain. (8.8.a)
28. ANALYZE Why would a denser fluid exert
stronger pressure on an object in the fluid
than a less dense fluid would?
29. PREDICT Ebony is a dark wood that has a density of 1.2 g/cm3. Water has a density of 1.0
g/cm3. Will a block of ebony float in water?
Explain. (8.8.d)
126 Unit 1: Motion and Forces
35. SYNTHESIZE Look back at the photograph on
pages 100–101. Explain how practicing
under water helps astronauts prepare for a
space mission.
36. PREDICT Refer to the chart on page 107.
Choose one of the liquids listed in the chart.
Pick five other substances from the chart.
Predict whether each of the five substances
would float or sink in the liquid that you chose.
Evaluate all of the data, results, and information
from your project folder. Prepare to present your
project to the class. Be ready to answer questions
posed by your classmates about your results.
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