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DATE CLASS

Use with Text Pages 78-82

• ConnectingMotion with Forces

T ;~tti~e:{j:L'!ire answers. Write a question for each answer. The first one has been done as an example.

1. pushorpull v~_'n_a_t_i_s_a_t_'o_r_ce_?_. _

L net force _

3. balanced forces

4. friction

5. inertia ~ _

6. Newton's first law of motion _

Study the diagram below. Then answer the following questions fJ1j circling the letter that best answers each question.

T

s

7. A person skis downhill from point R to point U. The speed of the skier increases in going frompoint R to point 5 because

a. only balanced forces act on the skier.b. an unbalanced force acts on the skier.

c. only inside forces act on the skier.d. no forces act on the skier.

8. The skier is able to coast between points 5 and T even though it is uphill because of

a. gravity. b. centripetal force. c. cohesive force. d. inertia.

J.The force that opposes motion between the skier's skis and the surface of the snow is

a.net. b. balanced. c. friction. d. inertia.

.. /Copynqht © GlencOe/McGraw-HilI. 3 division of The \t1cGraw-HiII Companies. Inc.

NAME DATE CLASS

Use with Text Pages 83-86

• Gravity-A Familiar Force

1. What is gravity?

Write answers to the jolloo.lJing questions on the blank lines protnded.

2. What are two things that the amount of gravitational force between two objects depends on?

3. Y'vnydoes Earth exert a stronger gravitational force than the moon? _

4. If an object weighs 40 N on Earth, would it weigh more than 40 N on the moon? Explain

your answer.

:1. If an object has a mass of 26 g on Earth, would its mass be less than 26 g on the moon?

Explain your answer. ~'''''"\

Circle the pict-ure in each set below that shows the greater gravitational force beiuieen the iuio objects.

25-K9 ooutder 50-kg boulderr-.~-- .•+-

"1 ! 30 on

'" ~A. E.rth E.rth

Hubble spacetelescope

~p.1-

Hubble spacetelescope

V/-''j -,-

i~16_kmorbit

i I

\~

10-km orbit

~ 2S-kg boulder

~ '(-r'--30m\-.l

B. Earth

~ 25-<g boulder

I t\ I

\ I\ II !

\ 1100m

-\ i\ I

1 I\ !,,-,

Earth

COPYright ~ Glencoej~1cGr3·.·,,-Hiii. 3 division or T.r,e ~",1cGra'.'v-HiilCompanies, Inc.17

DATE CLASS

~1l"~~Pfaellll*'i"7:""""",_. ;::>::..;;;;-: ; .." --.:,:.:.:~ .. ;,

• Exploring Motionand Forces

Part A. Vocabulary ReviewComplete the statements below by choosing the correct kzy iermts) from the following list. Write the correct termis) inthe blank to the left of each statement.

accelerationfrictionnewtons

forcenet forceweight

keepsvelocitydistance

speedbalanced forcesinertia

average speedgravityseat belt

1. __ is the rate of change in position.

2. Total distance traveled divided by total time of travel is ~~.

3. __ describes both speed and direction.

4. The rate of change of velocity is called __ .

5.6.7.S.

~:: 9.

10.

A person wearing a(n) __ becomes "part" of the car.

A(n) __ is a push or pull one body exerts on another body.

A(n)__ on an object always changes the velocity of the object.

Forces that are equal in size and opposite in directions are called

The tendency of an object to resist any change in its motion is called

Newton's first law of motion states that an object moving at aconstant velocity __ moving at that velocity unless a net forceacts on it.

11. The force that opposes motion between two surfaces that are touch-ing each other is called __ .

12. __ is the force that every object in the universe exerts on everyother object.

13. An object's __ is the measure of the force of gravity on thatobject.

14. The amount of gravitational force between two objects depends ontheir masses and the between them.

15. 'VVeightis measured in units called ---J while mass is measured inunits called grams and kilograms.

)

o

NAME DATE CLASS

Chapter 3 Review (continued)

Part B. Concept Review1. If Karen rode her bicycle 5 km to school in 30 minutes, what was her average speed? Give

your answer in km/h.

2. Graph the following data of a car trip.

Total distance (m) Totol time (5)

0 0

150 10

200 20

200 35

What is the average speed of the car from 0 to 10 s?

200 -------,----~~-,

E 1 SO :--~--~-~--'--~-----"-~'-'a;uC.;::l 100 c-----'--~----_i_---7--c------'VIo<1l;§ 50;-1 --'-------.----'--~-+_----+-__c___j

Io -'--~-----~----+-~-~

o 5 10 15 20 25 30 35 40

Total Time (5)

A car entering a freeway ramp accelerates from 14 mls to 25 m/s in 10 5. What is the car'saverage acceleration during this 10 s?

4. Use the graph below to calculate a bicyclist's average acceleration between 2 s and 8 s.

30 ~-----,.---,------,-----------,i

I25 :'---,-------''---i----;--r----c-~/''",'' .----'! , -,

'3 20 !i-----+----+---'---+------+--:~----i---~___'l,

E ':;- 15;-: -+---"---+--___':,,-L-----'-----'---l-----.-.;a; Ia; I

Q. 10 !r--l---~'---:------+--'-~-_--je---_iVI I i /1

1/ !5; /;/ j

1/ io V i

012 3 4 5 6 7 8 9

Time (5)

5. What are some reasons for a law requiring all passengers in cars to wear seat belts?

NAME DATE CLASS

Use with Text Pages 33-86

In the blank at the left, umie the letter of the term that correctly completes each sta.tement.

1. Every object in the universe exerts a force on every other object. nus force iscalleda. friction b. gravity

2. The measure of the force of gravity on an object is the object's __ .a. weight b. inertia

3. The amount of gravitational force between two objects depends on their __ .a. color and density b. mass and distance

4. Weight is measured in units called __ .a. Newtons b. seconds

5. The greater an object's __ , the stronger the gravitational force on it.a. mass b. velocity

6. Mass is measured in units calleda. meters and kilometers b. grams and kilograms

7. A scale uses the principle of __ to measure how much something weighs.a. acceleration b. balanced forces

8. Earth exerts a stronger gravitational force than the moon because __ hasmore mass.a. the moon b. Earth

9. The masses of your hand and your notebook are quite small, so the force of attrac-tion between them isa. strong b. weak

10. An object transported from the surface of Earth to the surface of the moon has itsweight __ .a. increased b. decreased

11. __ doesn't change with changes in gravity.a. mass b. weight

12. The __ mass an object has, the more that object weighs .•.a. more b. less

13. On Earth gravity exerts a(n) __ force on your body.a. upward b. downward

Coovriqht 9 Glencoe/McGraw-Hill, a division of The l.kGraw-Hil! Companies, Inc. 17

NAME DATE CLASS

Use with Text Panes 64-71

'. Motion and SpeedSasha, Kim, and Barry decided to have a lO-km bicycle race after school. They asked the coach to show them hau: far10 km was on the school track. They then had their race on the track. Their race results are shown on the time-distancegraph below. Use this graph to fill in the table of race results, calculate average speeds, and answer the questions.

10

9

8

_7E~6

~ 5c:~ 4o

3

2

1

oo 5 10 15 20 25 30 35 40 45 50 55 60

Time (minutes)

t> 7t>Kim 1/ !j/1/~ ~

V ~ 7.--Bor~ VV ./' 7

/ 1/ ~V Sosho

V t-:/'/ ~

V

WV/

~

Race Results

Cyclist Total distance Total time Average speed

Kim>

---

-'--.--,.-- ---- ~Sasha --- JBarry

I --1. Which cyclist kept a constant speed during the entire race? What was this speed? _

----------2. Which cyclist won the race? What was the winning time? ~ _

3. Which cyclist placed second in the race? What was second place time?

4. Which cyclist placed last? What was last place time? _

5. Which cyclist started. off fastest? __ _

Copyright © Glencoe/McGraw-Hili, a division of The McGraw-Hili Companies, me.

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