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SAMPLE C
ONTENT
© Target Publications Pvt. Ltd. No part of this book may be reproduced or transmitted in any form or by any means, C.D. ROM/Audio Video Cassettes or electronic, mechanical
including photocopying; recording or by any information storage and retrieval system without permission in writing from the Publisher.
STD. VII General Science
WORKBOOK
Printed at: Jasmine Art Printers Pvt. Ltd., Navi Mumbai
P.O. No. 107786
Written as per the revised syllabus prescribed by the Maharashtra State Bureau of Textbook Production and Curriculum Research, Pune.
TEID: 12534_JUP
Name: -----------------------------------------------------------------------------------------------------
School:-----------------------------------------------------------------------------------------------------
Standard: ------------------- Division: ------------------- Roll No.: --------------------
• A Quick revision of theory at the beginning of every chapter.
• Wide Variety of Questions to ensure chapter coverage.
• Oral Test in every chapter for knowledge testing.
• Apply your knowledge section to widen your knowledge spectrum.
• Activities/Projects that help in experiential learning.
• Unit Test and Semester Papers for thorough revision.
Salient Features
SAMPLE C
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Our Std. VII General Science Workbook comes replete with a quick recap of Concepts, Summative Questions, Oral Tests and Formative Questions. The goal of this book is to provide practice to students and to help them understand the concepts better. Every Chapter consists of Let’s Revise section at the beginning of the chapter that gives the readers an overview of the theory. The Summative Assessment section includes questions based on the theory of each chapter. The Apply Your Knowledge (Formative Assessment) part of the chapters includes Activity Based Questions along with Project Work. Each chapter comes with an exclusive section called Oral Test, which has been prepared to test the chapter knowledge of a student. All the chapters have been covered extensively through the medium of practice questions and activities. The book comprises of four Unit Tests, which would help students in thorough revision of the chapters. The book also includes two Semester Papers that give students a chance to test their knowledge quotient based on what they've learned so far. We hope this book turns out to be a guiding light for the students of Std. VII and helps them to prepare for their examination. The journey to create a complete book is strewn with triumphs, failures and near misses. If you think we’ve nearly missed something or want to applaud us for our triumphs, we’d love to hear from you. Please write to us at: [email protected] A book affects eternity; one can never tell where its influence stops.
Best of luck to all the aspirants! From, Publisher Edition: Second
Disclaimer This reference book is transformative work based on textual contents published by Bureau of Textbook. We the publishers are making this reference book which constitutes as fair use of textual contents which are transformed by adding and elaborating, with a view to simplify the same to enable the students to understand, memorize and reproduce the same in examinations. This work is purely inspired upon the course work as prescribed by the Maharashtra State Bureau of Textbook Production and Curriculum Research, Pune. Every care has been taken in the publication of this reference book by the Authors while creating the contents, the Authors and the Publishers shall not be responsible for any loss or damages caused to any person on account of errors or omissions which might have crept in or disagreement of any third party on the point of view expressed in the reference book. © reserved for all the contents created by our Authors. No copyright is claimed in the textual contents which are presented as part of fair dealing with a view to provide best supplementary study material for the benefit of students.
SAMPLE C
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No. Topic Name Page No. 1. The Living World : Adaptations and Classification 1
2. Plants : Structure and Function 14
3. Properties of Natural Resources 28
4. Nutrition in Living Organisms 42
5. Food Safety 58
Unit Test 1 70
6. Measurement of Physical Quantities 72
7. Motion, Force and Work 81
8. Static Electricity 91
9. Heat 103
10. Disaster Management 113
Unit Test 2 124
First Semester 126
11. Cell Structure and Micro-organisms 128
12. The Muscular System and Digestive System in Human Beings 144
13. Changes - Physical and Chemical 157
14. Elements, Compounds and Mixtures 169
15. Materials we Use 188
Unit Test 3 198
16. Natural Resources 200
17. Effects of Light 215
18. Sound : Production of Sound 224
19. Properties of a Magnetic Field 233
20. In the World of Stars 241
Unit Test 4 250
Second Semester 252
Note: Textual Questions are represented by * mark.
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81
7. Motion, Force and Work
Let’s Revise
1. The actual length of the route traversed by a moving body irrespective of direction iscalled as distance. It is a scalar quantity with SI unit metre.
2. The minimum distance traversed by a moving body in a particular direction along astraight line is called displacement. It is a vector quantity with SI unit metre.
3. The distance traversed by a moving body irrespective of the direction in unit time is called as speed of the body. It is a scalar quantity with SI unit: metre per second (m/s).
Speed = Distance coveredTime required to cover the distance
4. The distance traversed by a body in a specific direction in unit time is called as velocityof the body. It is a vector quantity with SI unit: metre per second (m/s).
Velocity = DisplacementTotal time
i. Velocity of a body can be changed by changing speed of the body or by changingits direction of motion.
ii. Average velocity of a body is displacement of the body divided by time intervalin which displacement occurs. It is constant for an entire route.
iii. The velocity of a body at a particular moment of time (instant) is calledinstantaneous velocity. It can be different at different times.
5. Acceleration is change in velocity per second. It is a vector quantity with SI unit: metre per second square (m/s2).
Acceleration = Change in velocityTime taken for change
Increasing or decreasing the velocity causes acceleration. 6. The interaction that brings about acceleration is called force. It is a vector quantity
with SI unit newton (N) and CGS unit dyne. i. Force is measured by the acceleration it produces. ii. When 1 kilogram standard mass is pulled with an acceleration of 1 m/s2 on a
frictionless surface, the force applied is called 1 newton (1 N). 7. Newton’s first law of motion: A stationary body remains in stationary state or a body
in motion continues to move with same speed in the same direction if no force acts onthe body.
8. Work (W) done by the force on the body depends on the force (F) applied to the bodyand displacement (s) caused by it. i.e., W = F s
i. It is a scalar quantity. ii. MKS unit of work : joule (J) CGS unit of work : erg iii. When a force of 1 N applied on body parallel to the surface upon which the body
is placed causes displacement of 1 m in the body along the direction of the forcethen, work done on the body by the force is said to be 1 joule (1 J).
SAMPLECONTENT
Std. VII: General Science Workbook
82
Fill in the blanks *1. Fill in the blanks with the proper words from the brackets.
(stationary, zero, changing, constant, displacement, velocity, speed, acceleration, stationary but not zero, increases)
i. If a body traverses a distance in direct proportion to the time, the speed of the body is
------------------------.
ii. If a body is moving with a constant velocity its acceleration is ------------------------.
iii. ------------------------ is a scalar quantity.
iv. ------------------------ is the distance traversed by a body in a particular direction in unit
time.
Odd one out 1. m/s, dyne, km/hr, cm/s.
Ans: --------------------------------------------------------------------------------------------------------------
2. Acceleration, work, energy, speed.
Ans: -------------------------------------------------------------------------------------------------------------- Match the following
*1. From the groups B and C, choose the proper words, for each of the words in group A.
Group ‘A’ Answers Group ‘B’ Group ‘C’
i. Work ---------------------------------- a. newton x. erg
ii. Force ---------------------------------- b. metre y. cm
iii. Displacement ---------------------------------- c. joule z. dyne
How are we different? 1. Distance and Displacement. Ans:
Distance Displacement
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Summative Evaluation
Q
Q
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Q
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Chapter 7: Motion, Force and Work
83
2. Speed and Velocity. Ans:
Speed Velocity
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------------------------------------------------ Answer in one sentence 1. Why is displacement a vector quantity?
Ans: --------------------------------------------------------------------------------------------------------------
2. Intext Question. (Textbook page no.46) i. What is meant by speed?
Ans: -------------------------------------------------------------------------------------------------------------- ii. What is the formula for calculating speed?
Ans: -------------------------------------------------------------------------------------------------------------- 3. Intext Question. (Textbook page no. 48) What is the cause of acceleration?
Ans: -------------------------------------------------------------------------------------------------------------- 4. Use your brain power! (Textbook page no. 49) Acceleration is a vector quantity. Is force a vector quantity, too?
Ans: -------------------------------------------------------------------------------------------------------------- Answer in your own words *1. Explain the following concepts in your own words with everyday examples: Force, work, displacement, velocity, acceleration, distance.
Force: ----------------------------------------------------------------------------------------------------------
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Work: -----------------------------------------------------------------------------------------------------------
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Q
Q
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Std. VII: General Science Workbook
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Displacement: ---------------------------------------------------------------------------------------------------
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Distance: --------------------------------------------------------------------------------------------------------
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Velocity: ---------------------------------------------------------------------------------------------------------
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Acceleration: ----------------------------------------------------------------------------------------------------
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Chapter 7: Motion, Force and Work
85
Answer the following 1. Intext Question. (Textbook page no. 47) Let’s find the unit.
Task Speed Velocity Write the formula Speed =--------------- Velocity =---------------
Write the units of the quantities
Distance: ---------------
Time period: ---------------
Displacement: ---------------
Time period: --------------- Insert the units instead of quantities in the formulae. You will get the unit of speed and velocity. Unit of speed:--------------- Unit of velocity: ---------------
2. Use your brain power! (Textbook page no. 48) The unit of acceleration is m/s2. Verify this.
Ans: --------------------------------------------------------------------------------------------------------------
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-------------------------------------------------------------------------------------------------------------------- *3. A bird sitting on a wire, flies, circles around and comes back to its perch. Explain the total
distance it traversed during its flight and its eventual displacement.
Ans: --------------------------------------------------------------------------------------------------------------
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-------------------------------------------------------------------------------------------------------------------- Solve the following
*1. Observe the figure and answer the questions. Sachin and Sameer started on a motorbike from place A,
took the turn at B, did a task at C, travelled by the route CD to D and then went on to E. Altogether, they took one hour for this journey. Find out (i) the actual distance traversed by them and (ii) the displacement from A to E. (iii) From this, deduce their speed. (iv) What was their velocity from
A to E in the direction AE? (v) Can this velocity be called average velocity?
Solution: --------------------------------------------------------------------------------------------------------
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4 km 5 km
C
B DEA 3 km 3 km 3 km
Q
Q
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Std. VII: General Science Workbook
86
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-------------------------------------------------------------------------------------------------------------------- *2. A ball is rolling from A to D on a flat and smooth surface. Its speed is 2 cm/s. On reaching B,
it was pushed continuously up (forward) to C. On reaching D from C, its speed had become 4 cm/s. It took 2 seconds for it to go from B to C. What is the acceleration of the ball as it goes from B to C?
Solution: --------------------------------------------------------------------------------------------------------
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-------------------------------------------------------------------------------------------------------------------- *3. A force of 1000 N was applied to stop a car that was moving with a constant velocity. The
car stopped after moving through 10 m. How much is the work done?
Solution: --------------------------------------------------------------------------------------------------------
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-------------------------------------------------------------------------------------------------------------------- *4. A cart with mass 20 kg went 50 m in a straight line on a plain and smooth road when a force
of 2 N was applied to it. How much work was done by the force?
Solution: --------------------------------------------------------------------------------------------------------
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-------------------------------------------------------------------------------------------------------------------- 5. Complete the table.
Change in velocity Time taken for change Acceleration
i. 50 km/hr 30 minutes -----------------------
ii. ----------------------- 3 minutes 1 cm/s2
iii. 30 m/s ----------------------- 6 m/s2
B C DA
SAMPLE C
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Chapter 7: Motion, Force and Work
87
Solution: --------------------------------------------------------------------------------------------------------
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displaced through displacement of 50 cm. The work done on the block is 2500 erg then, how much force is applied on the block by weight?
Solution: --------------------------------------------------------------------------------------------------------
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-------------------------------------------------------------------------------------------------------------------- 7. A bus covers the distance of 100 km between its starting point at depot and the first bus
stop in 2 hours, the distance of 80 km between two bus stops in one and half hours and the distance of 120 km between second bus stop and its destination point in two and half hours, what is the average velocity of the bus if it has moved in straight line throughout the journey?
Solution: --------------------------------------------------------------------------------------------------------
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1. What does Newton’s first law of motion state? 2. What is the unit of work in SI system? 3. What is the acceleration produced by a car moving with constant velocity? 4. What is the formula for calculating velocity? 5. When is the work done said to be 1 joule?
Block Pulley
Weight
Oral Test
SAMPLE C
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Std. VII: General Science Workbook
88
1. Observe and Discuss. (Textbook page no. 46) Observe the images given below and discuss them. 2. Let’s recall. (Textbook page no. 46) What is meant by motion? What causes a change in motion?
Ans: --------------------------------------------------------------------------------------------------------------
-------------------------------------------------------------------------------------------------------------------- 3. Intext Question. (Textbook page no. 47) If the truck traverses the 10 km distance AB in 10 minutes, BC in 20 minutes and CD in
30 minutes, then
Velocity for the distance AB in km/hr = 10 km10 minutes
= 60 km60 minutes
= 60 km/hr Now deduce the velocities for the distances BC and CD.
Ans: --------------------------------------------------------------------------------------------------------------
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B C DA10 km 10 km 20 km
Apply Your Knowledge
SAMPLE C
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Chapter 7: Motion, Force and Work
89
4. Intext Question. (Textbook page no. 48) i. When a toy car that runs on a clockwork spring is released on a flat floor, after winding up the
spring, it goes in a straight line. However, when it is hit on one side, it changes direction and keeps going. If it collides into a wall, it stops. It means that its velocity changes. How did this change take place?
Ans: --------------------------------------------------------------------------------------------------------------
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-------------------------------------------------------------------------------------------------------------------- ii. On a football ground, how does the direction of the ball moving in a straight line, change?
Ans: --------------------------------------------------------------------------------------------------------------
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-------------------------------------------------------------------------------------------------------------------- 5. Try this. (Textbook page no. 48) Take a glass marble and let it roll on a big smooth tabletop. After some time its velocity will
decrease and it will stop. On a carrom board, too, the carrom coin, pushed by a striker will move forward some distance, and then come to a stop. If the coin is pushed after applying talcum powder to the carrom board, it will keep moving for a longer time and then come to a stop.
What can we infer from this?
Ans: --------------------------------------------------------------------------------------------------------------
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-------------------------------------------------------------------------------------------------------------------- 6. Intext Question. (Textbook page no. 49) In the figure alongside, a string, attached to a wooden block on a
table, is passed over a pulley and tied to a weight. On applying a sufficient weight, the block will be seen to move.
i. Which force is being applied here?
Ans: -------------------------------------------------------------------------------------------------------------- ii. How can this force be increased?
Ans: --------------------------------------------------------------------------------------------------------------
Woodenblock Pulley
Weight
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Std. VII: General Science Workbook
90
iii. What will happen on applying more force?
Ans: -------------------------------------------------------------------------------------------------------------- iv. When can we say that work is done by the applied force?
Ans: -------------------------------------------------------------------------------------------------------------- v. If the block moves forward, we can say that it has been displaced. Due to the displacement, we
say that the force has done some work. Can we measure this work?
Ans: -------------------------------------------------------------------------------------------------------------- Activity / Project
*1. Collect information about the study made by Sir Isaac Newton regarding force and acceleration and discuss it with your teacher.
2. Try this. (Textbook page no. 49) Place a weight of 1 kilogram on a smooth wooden table. Spread some talcum powder evenly
on the table. Now pull the 1 kg weight with an acceleration of 1 m/s2. Again pull it with an acceleration of 2 m/s2. It means that, now, you have applied a force of 2 N. You will have to take many trials for this experiment.
3. Crossword.
Across: 1. Total path length of
route travelled.
2. Increase in velocity
causes -------------
3. ------------- = Force
displacement Down:
1. Speed is -------------
Quantity. 2. CGS unit of work.
3. ------------- is measured by acceleration produced due to it.
Q
1a 1d
3d
2a 2d
3a
Grades: A - Excellent Teacher’s Remark:------------------------------------------------------------
B - Good ---------------------------------------------------------------------------------- C - Fair Date:-------------------- Sign:--------------------------
