Name _______________________________________________ Date ________________ Class______________

DIRECTED READING WORKSHEETS 53

15. How does a fish’s swim bladder cause the fish to move like asubmarine?

Review (p. 172)

Now that you’ve finished Section 2, review what you learned byanswering the Review questions in your ScienceLog.

Section 3: Bernoulli’s Principle (p. 173)

1. What happens to your shower curtain when you increase thewater pressure in your shower?

Fluid Pressure Decreases as Speed Increases (p. 173)

2. What did Bernoulli say about the speed of a moving fluid?

a. The faster the speed, the higher the pressure.b. The slower the speed, the lower the pressure.c. The faster the speed, the lower the pressure.d. The slower the speed, the higher the pressure.

3. The table-tennis ball in Figure 14 stays in the water stream. Why?

It’s a Bird! It’s a Plane! It’s Bernoulli’s Principle! (p. 174)

4. Look at Figure 15. The shape of an airplane wing causes the air

above the wing to flow than theair below it. (slower or faster)

5. The upward force acting on an airplane wing due to air flow is

called . (buoyancy or lift)

Chapter 7, continuedC

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Thrust and Wing Size Determine Lift (p. 175)

6. How does thrust increase lift?

7. How large must the wings be for each of the following airplanetypes? (Circle one for each type.)

a. small commuter plane small medium large

b. high-performance jet small medium large

c. glider small medium large

8. Which of the methods below do birds use to stay in the air?(Circle all that apply.)

a. They use large wing size to glide on wind currents.b. They pull up their legs.c. They move their tails up and down.d. They flap their wings.

Drag Opposes Motion in Fluids (p. 176)

9. In a strong wind, drag is the thatyou walk against.

10. usually causes drag forces in flight.

11. Wing flaps are parts of a commercial airplane that reduce drag.

True or False? (Circle one.)

Wings Are Not Always Required (p. 177)

12. Take a moment to examine Figure 19. A baseball with a side spin

will curve the side where the ball ismoving in the same direction as the air flow. (away from or toward)

Review (p. 177)

Now that you’ve finished Section 3, review what you learned byanswering the Review questions in your ScienceLog.

Name _______________________________________________ Date ________________ Class______________

54 HOLT SCIENCE AND TECHNOLOGY

Chapter 7, continued

Cop

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by

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Name _______________________________________________ Date ________________ Class______________

DIRECTED READING WORKSHEETS 53

15. How does a fish’s swim bladder cause the fish to move like asubmarine?

As the swim bladder fills with gases, the fish’s overall density decreases

and the fish rises. As the swim bladder empties of gases, the fish’s overall

density increases and the fish sinks.

Review (p. 172)

Now that you’ve finished Section 2, review what you learned byanswering the Review questions in your ScienceLog.

Section 3: Bernoulli’s Principle (p. 173)

1. What happens to your shower curtain when you increase thewater pressure in your shower?

The curtain swirls around my legs.

Fluid Pressure Decreases as Speed Increases (p. 173)

2. What did Bernoulli say about the speed of a moving fluid?

a. The faster the speed, the higher the pressure.b. The slower the speed, the lower the pressure.c. The faster the speed, the lower the pressure.d. The slower the speed, the higher the pressure.

3. The table-tennis ball in Figure 14 stays in the water stream. Why?

The air, which has a higher pressure, pushes the ball into the water

stream, which has a lower pressure.

It’s a Bird! It’s a Plane! It’s Bernoulli’s Principle! (p. 174)

4. Look at Figure 15. The shape of an airplane wing causes the air

above the wing to flow than theair below it. (slower or faster)

5. The upward force acting on an airplane wing due to air flow is

called . (buoyancy or lift)lift

faster

Chapter 7, continuedC

opyr

ight

© b

y H

olt,

Rin

ehar

t an

d W

inst

on.

All

right

s re

serv

ed.

CH

AP

TER

7

▼▼▼

Thrust and Wing Size Determine Lift (p. 175)

6. How does thrust increase lift?

Greater thrust means greater speed, which means faster air and

increased lift.

7. How large must the wings be for each of the following airplanetypes? (Circle one for each type.)

a. small commuter plane small medium large

b. high-performance jet small medium large

c. glider small medium large

8. Which of the methods below do birds use to stay in the air?(Circle all that apply.)

a. They use large wing size to glide on wind currents.b. They pull up their legs.c. They move their tails up and down.d. They flap their wings.

Drag Opposes Motion in Fluids (p. 176)

9. In a strong wind, drag is the thatyou walk against.

10. usually causes drag forces in flight.

11. Wing flaps are parts of a commercial airplane that reduce drag.

True or False? (Circle one.)

Wings Are Not Always Required (p. 177)

12. Take a moment to examine Figure 19. A baseball with a side spin

will curve the side where the ball ismoving in the same direction as the air flow. (away from or toward)

Review (p. 177)

Now that you’ve finished Section 3, review what you learned byanswering the Review questions in your ScienceLog.

toward

Turbulence

force

Name _______________________________________________ Date ________________ Class______________

54 HOLT SCIENCE AND TECHNOLOGY

Chapter 7, continued

Cop

yrig

ht ©

by

Hol

t, R

ineh

art

and

Win

ston

. A

ll rig

hts

rese

rved

.