Caution! Unverified Website!
The identity of this user has not yet been verified. Please make transactions at your own risk!
Aman Sir
motion class 7 physical science icse board
Not Available
Description
motion
KnowledgeBoat Logo
Home
Class 7 - Concise Physics Selina Solutions
Motion
Search by lesson title
Chapter 1
Physical Quantities and Measurement
Chapter 2
Motion
Chapter 3
Energy
Chapter 4
Light Energy
Chapter 5
Heat
Chapter 6
Sound
Chapter 7
Electricity and Magnetism
Chapter 2
Motion
Class 7 - Concise Physics Selina Solutions
Objective Questions
Question 1
Write true or false for each statement:
(a) Two trains going in opposite directions with the same speed are at rest relative to each other.
(b) A ball is thrown vertically upwards. Its motion is uniform throughout.
(c) The motion of a train starting from one station and reaching at another station is non-uniform.
(d) A motion which repeats itself after a fixed interval of time is called periodic motion.
(e) A ball thrown by a boy from a roof-top has oscillatory motion.
(f) Mass has both magnitude and direction.
(g) Weight always acts vertically downwards.
(h) Mass varies from place to place but weight does not.
Answer
(a) False
Correct Statement — Two trains going in opposite directions with the same speed are at motion relative to each other.
(b) False
Correct Statement — A ball is thrown vertically upwards. Its motion is non-uniform throughout.
(c) True
(d) True
(e) False
Correct Statement — A ball thrown by a boy from a roof-top has curvilinear motion.
(f) False
Correct Statement — Mass has only magnitude.
(g) True
(h) False
Correct Statement — Weight varies from place to place but mass does not.
Question 2
Fill in the blanks:
(a) Two boys cycling on the road with the same speed are ................... relative to each other.
(b) The motion in a .................. is rectilinear motion.
(c) One to and fro motion of a clock pendulum takes time = .................. .
(d) 36 km h-1 = ....................... m s-1.
(e) Total distance travelled = .................... x total time taken.
(f) The weight of a girl is 36 kgf. Her mass will be .................. .
(g) The weight of a body is measured using ..................... .
Answer
(a) at rest
(b) straight line
(c) 2 s
(d) 10
(e) average speed
(f) 36 kg
(g) spring balance
Question 3
Match the following:
Column A Column B
(a) circular motion (i) a running fan
(b) periodic motion (ii) a car moving in a market
(c) vibratory motion (iii) movement of the hands of a clock
(d) rotatory motion (iv) motion of wire of a guitar
(e) non-uniform motion (v) motion of pendulum of a clock
Answer
Column A Column B
(a) circular motion (iii) movement of the hands of a clock
(b) periodic motion (v) motion of pendulum of a clock
(c) vibratory motion (iv) motion of wire of a guitar
(d) rotatory motion (i) a running fan
(e) non-uniform motion (ii) a car moving in a market
Question 4a
Select the correct alternative:
A book lying on a table is an example of:
a body at rest
a body in motion
a body neither at rest nor in motion
none of these
Answer
a body at rest
Reason — A book lying on a table will not change its position if it is not disturbed, so it is said to be at rest.
Question 4b
Select the correct alternative:
The motion of a pendulum is:
rotatory
oscillatory
curvilinear
rectilinear
Answer
oscillatory
Reason — The motion of pendulum is to and fro motion which is called oscillatory motion.
Question 4c
Select the correct alternative:
A car moving on a straight road is an example of:
rotatory motion
rectilinear motion
oscillatory motion
periodic motion
Answer
rectilinear motion
Reason — As the car is moving on a straight road so it is in rectilinear motion.
Question 4d
Select the correct alternative:
A ball falls down vertically. Its motion is:
periodic
linear
circular
vibratory
Answer
linear
Reason — A ball falls down vertically i.e. in a straight line, so its motion is linear.
Question 4e
Select the correct alternative:
If a body covers equal distances in equal intervals of time, the motion is said to be:
uniform
non-uniform
oscillatory
rotatory
Answer
uniform
Reason — If a moving body travels equal distances in equal intervals of time, then the motion is said to be uniform.
Question 4f
Select the correct alternative:
A boy goes from his house to school by bus at a speed of 20 km h-1 and returns back through the same route at a speed of 30 km h-1. The average speed of his journey is:
24 km h-1
25 km h-1
30 km h-1
20 km h-1
Answer
24 km h-1
Reason — Suppose the distance between school and house is D km.
In first part the boy goes to school by bus from home at speed (V1) = 20 km h-1.
time taken (t1) =
distance
speed
speed
distance
=
D
20
20
D
In second part the boy returns from school to home through same route at speed(V2) = 30 km h-1.
time taken (t2) =
distance
speed
speed
distance
=
D
30
30
D
Total distance = D + D = 2D km
Total time taken =
D
20
20
D
+
D
30
30
D
=
5D
60
60
5D
Average speed =
total distance travelled
total time taken
total time taken
total distance travelled
Speed
=
distance
time
=
2
𝐷
5
𝐷
60
=
2
×
12
=
24
km h
−
1
Speed=
time
distance
=
60
5D
2D
=2×12
=24km h
−1
Question 4g
Select the correct alternative:
The earth attracts a body of mass 1 kg with a force of 10 N. The mass of a boy is 50 kg. His weight will be:
50 kg
500 N
50 N
5 N
Answer
500 N
Reason — Weight = 50 x 10 = 500 N
Short/Long Answer Questions
Question 1
Explain the meaning of the terms rest and motion.
Answer
A body is said to be at rest if it does not change its position with respect to its immediate surroundings.
A body is said to be in motion if it changes its position with respect to its immediate surroundings.
Question 2
Comment on the statement 'rest and motion are relative terms'. Give an example.
Answer
An object can be in motion relative to one set of objects while at rest relative to some other set of objects. Thus, rest and motion are relative terms.
Example — If a boy is sitting on a bench in a bus stop and he sees a moving bus, for him the bus is in motion but the trees near by will appear to him at rest.
But a boy who is sitting inside a bus, to him the trees and the boy outside sitting on the bench will appear to move in opposite direction. But the roof of the bus and driver will appear to him at rest.
From the above example it can be concluded that rest and motion are relative terms.
Question 3
Fill in the blanks using one of the words: at rest, in motion.
(a) A person walking in a compartment of a stationary train is ................... relative to the compartment and is ................... relative to the platform.
(b) A person sitting in a compartment of a moving train is .................... relative to the other person sitting by his side and is ....................... relative to the platform.
Answer
(a) in motion, in motion
(b) at rest, in motion
Question 4
Name five different types of motion you know.
Answer
The five different types of motion are:
Translatory motion
Circular motion
Oscillatory motion
Vibratory motion
Rotatory motion
Question 5
What do you mean by translatory motion? Give one example.
Answer
A body is said to have translatory motion if every point on the moving body moves through the same distance in the same interval of time.
Example — Motion of a box when pushed from one corner of a room to the other.
Question 6
Explain the meanings of:
(i) rectilinear motion
(ii) curvilinear motion
Give one example of each.
Answer
(i) The motion of a body in a straight line is called rectilinear or linear motion.
Example — A car moving on a straight road.
(ii) If the motion of a body is along a curved path, it is said to be a curvilinear motion.
Example — The motion of a cycle while taking a turn on the road.
Question 7
What is rotatory motion? Give two examples.
Answer
A body is said to be in a rotatory motion if it moves about a fixed axis.
Examples — a spinning top, a merry-go-round.
Question 8
What is meant by circular motion? Give one example.
Answer
The motion of a body along a circular path is called circular motion. Example — Motion of a satellite around the earth.
Question 9
How does rotatory motion differ from circular motion?
Answer
Rotatory motion Circular motion
In rotatory motion, the axis of rotation passes from a point in the body itself. In circular motion, the axis of revolution passes through a point outside the body.
Motion of earth about its own axis is a rotational motion. Motion of satellite around the earth is a circular motion.
Question 10
Explain oscillatory motion by giving one example.
Answer
The to and fro motion of a body from its rest position is called the oscillatory motion.
Example — Motion of a pendulum of a wall clock. The bob of pendulum moves to side A from its rest position O, again comes back to position O and then moves to side B and then comes back to rest position O. This process is continuously repeated and this to and fro motion is called oscillatory motion.
Explain oscillatory motion by giving one example. Motion, Concise Physics Solutions ICSE Class 7.
Question 11
What is vibratory motion? Give one example.
Answer
The to and fro motion of a part of the body keeping its rest part fixed is called vibratory motion.
Example — Vibration of the membrane of tabla.
Question 12
Differentiate between periodic and non-periodic motions by giving an example of each.
Answer
Periodic motion Non-periodic motion
A motion which gets repeated after a regular interval of time is called a periodic motion. The motion which does not repeat itself after a regular interval of time is called non-periodic motion.
Example — Pendulum of a wall clock repeats its motion after every 2 s. Example — A footballer running on a field.
Question 13
What is random motion? Give an example.
Answer
The motion of an object which takes path in no specific direction is called random motion.
Example — Motion of molecules of a gas.
Question 14
Name the type/types of motion being performed by each of the following:
(a) Vehicle on a straight road.
(b) Blades of an electric fan in motion.
(c) Pendulum of a wall clock.
(d) Smoke particles from chimney.
(e) Hands of a clock.
(f) Earth around the Sun.
(g) A spinning top.
Answer
(a) Rectilinear motion
(b) Rotatory motion
(c) Oscillatory motion and Periodic motion
(d) Non-periodic motion
(e) Circular motion
(f) Periodic motion, circular motion
(g) Rotatory motion
Question 15
Give two examples to illustrate that a body can have two or more types of motion simultaneously.
Answer
The two examples that show a body can have two or more types of motion (mixed motion) simultaneously are:
The Earth rotates about its axis (rotatory motion) and at the same time, it revolves around the sun in a curved path (curvilinear or circular motion) in a fixed time interval (periodic motion).
A ball rolling on the ground has rotatory and translatory motion as it moves on the ground.
Question 16
State the types of motion of the following:
(a) The needle of a sewing machine
(b) The wheel of a bicycle
(c) The drill machine
(d) The carpenter's saw
Answer
(a) Periodic motion
(b) Translatory and rotatory motion
(c) Translatory and rotatory motion
(d) Translatory and oscillatory motion
Question 17
Distinguish between uniform and non-uniform motions, giving an example of each.
Answer
Uniform motion Non-uniform motion
If a moving body travels equal distances in equal intervals of time, its motion is said to be uniform. If a moving body travels unequal distances in equal intervals of time, its motion is said to be non-uniform.
Example — A car covering same distance in same interval of time at constant speed in a straight line. Example — Motion of a bicycle in a busy road.
Question 18
How do you determine the average speed of a body in non-uniform motion?
Answer
The average speed is calculated by finding the ratio of the total distance travelled by the body to the total time taken in the journey.
Average speed =
total distance travelled
total time taken
total time taken
total distance travelled
Question 19
Define the term weight and state its S.I. unit.
Answer
The weight of the body on earth is the force with which earth attracts the body. The S.I. unit of weight is newton (N).
Question 20
How are the units of weight, kgf and newton related?
Answer
1 kgf = 9.8 (nearly 10) N
Question 21
State three differences between mass and weight.
Answer
Mass Weight
Mass is the quantity of matter contained in a body. Weight is the force with which the earth attracts the body.
It is measured by a beam balance. It is measured by a spring balance.
Its S.I. unit is kilogram(kg). Its S.I. unit is newton (N).
Question 22
Which quantity: mass or weight, does not change by change of place?
Answer
Mass does not change by change of place.
Question 23
State which of the quantities, mass or weight is always directed vertically downwards.
Answer
The direction of weight is always directed vertically downwards.
Numericals
Question 1
A car covers a distance of 160 km between two cities in 4 h. What is the average speed of the car?
Answer
Distance = 160 km;
time = 4 h
Average Speed
=
Total distance travelled
total time taken
Average Speed
=
160
4
=
40
km h
−
1
Average Speed=
total time taken
Total distance travelled
Average Speed=
4
160
=40km h
−1
So, average speed of the car = 40 km h-1.
Question 2
A train travels a distance of 300 km with an average speed of 60 km h-1. How much time does it take to cover the distance?
Answer
Distance = 300 km;
Average speed = 60 km h-1
time = ?
Average speed
=
Distance travelled
time
60
=
300
time
time
=
300
60
=
5
hr
Average speed=
time
Distance travelled
60=
time
300
time=
60
300
=5hr
So, time taken = 5 hour.
Question 3
A boy travels with an average speed of 10 m s-1 for 20 min. How much distance does he travel?
Answer
Average speed = 10 m s-1;
time = 20 min
1 min = 60 sec
20 min = 60 x 20 = 1200 sec
distance = ?
Average speed
=
distance
time
10
=
distance
1200
distance
=
1200
×
10
=
12000
m
Average speed=
time
distance
10=
1200
distance
distance=1200×10=12000m
So, distance covered = 12000 m or 12 km.
Question 4
A boy walks a distance of 30 m in 1 minute and another 30 m in 1.5 minute. Describe the type of motion of the boy and find his average speed in m s-1.
Answer
The motion of the boy is non-uniform.
total distance travelled = 30 m + 30 m = 60 m
total time taken = 1 min + 1.5 min = 2.5 min
1 min = 60 sec
2.5 min = 2.5 x 60 = 150 sec
Average speed = ?
Average Speed
=
Total distance travelled
total time taken
Average Speed
=
60
150
=
0.4
m s
−
1
Average Speed=
total time taken
Total distance travelled
Average Speed=
150
60
=0.4m s
−1
So, average speed of the boy = 0.4 m s-1.
Question 5
A cyclist travels a distance of 1 km in the first hour, 0.5 km in the second hour and 0.3 km in the third hour. Find the average speed of the cyclist in:
(i) km h-1
(ii) m s-1.
Answer
(i) total distance travelled = 1 km + 0.5 km + 0.3 km = 1.8 km
total time taken = 1 h + 1 h + 1 h = 3 h
Average Speed
=
Total distance travelled
total time taken
Average Speed
=
1.8
3
=
0.6
km h
−
1
Average Speed=
total time taken
Total distance travelled
Average Speed=
3
1.8
=0.6km h
−1
So, average speed of the cyclist = 0.6 km h-1.
(ii) total distance travelled = 1 km + 0.5 km + 0.3 km = 1.8 km
1 km = 1000 m
1.8 km = 1.8 x 1000 = 1800 m
total time taken = 1 h + 1 h + 1 h = 3 h
1 h = 3600 sec
3 h = 3 x 3600 = 10800 sec
Average Speed
=
Total distance travelled
total time taken
Average Speed
=
1800
10800
=
0.167
m s
−
1
Average Speed=
total time taken
Total distance travelled
Average Speed=
10800
1800
=0.167m s
−1
So, average speed of the cyclist = 0.167 m s-1.
Question 6
A car travels with speed 30 km h-1 for 30 minutes and then with speed 40 km h-1 for 1 hour. Find:
(a) the total distance travelled by the car.
(b) the total time of travel, and
(c) the average speed of the car.
Answer
(a) In first part of journey
speed = 30 km h-1
time = 30 min
60 min = 1 h
30 min =
1
2
2
1
h
Speed
=
distance
time
30
=
distance
1
2
distance
=
30
×
1
2
=
15
km
Speed=
time
distance
30=
2
1
distance
distance=30×
2
1
=15km
In second part of journey
speed = 40 km h-1
time = 1 h
Speed
=
distance
time
40
=
distance
1
distance
=
40
×
1
=
40
km
Speed=
time
distance
40=
1
distance
distance=40×1=40km
So, total distance travelled = 15 km + 40 km = 55 km.
(b) time taken in first part of journey = 30 min
60 min = 1 h
30 min =
1
2
2
1
h
time taken in second part of journey = 1 h
total time taken = 1 h +
1
2
2
1
h = 1.5 h
So, total time taken = 1.5 h.
(c)
Average Speed
=
Total distance travelled
total time taken
Average Speed
=
55
1.5
=
36.67
km h
−
1
Average Speed=
total time taken
Total distance travelled
Average Speed=
1.5
55
=36.67km h
−1
So, average speed of the car = 36.67 km h-1.
Question 7
On earth the weight of a body of mass 1.0 kg is 10 N. What will be the weight of a boy of mass 37 kg in
(a) kgf
(b) N
Answer
(a) Mass of boy = 37 kg
So, Weight of boy in kgf = 37 kgf.
(b) 1 kgf = 10 N
37 kgf = 37 x 10 = 370 N
So, weight of boy in N = 370 N.
Question 8
The weight of a body of mass 6.0 kg on moon is 10 N. If a boy of mass 30 kg goes from earth to the moon surface, what will be his
(a) mass,
(b) weight?
Answer
(a) Mass of boy = 30 kg on moon surface as mass remains constant. Mass of a body does not change with place.
(b) Weight of body of mass 6.0 kg on moon surface = 10 N
Weight of body of mass 30 kg on moon surface =
10
6.0
6.0
10
x 30 = 50 N
So, weight of boy of 30 kg on moon surface = 50 N.
Prev
Physical Quantities and Measurement
Next
Energy
CONTENTS
Objective Questions
Short/Long Answer Questions
Numericals
ICSE/ISC TEXTBOOK SOLUTIONS
Class - 6 Concise Biology Selina Solutions
Class - 6 Veena Bhargava Geography Solutions
Class - 6 Effective History & Civics Solutions
Class - 7 Concise Physics Selina Solutions
Class - 7 Concise Chemistry Selina Solutions
Class - 7 Dalal Simplified Middle School Chemistry Solutions
Class - 7 Concise Biology Selina Solutions
Class - 7 Living Science Biology Ratna Sagar Solutions
Class - 7 Around the World Geography Solutions
Class - 7 Veena Bhargava Geography Solutions
Class - 7 Effective History & Civics Solutions
Class - 8 Concise Physics Selina Solutions
Class - 8 Concise Chemistry Selina Solutions
Class - 8 Dalal Simplified Middle School Chemistry Solutions
Class - 8 Concise Biology Selina Solutions
Class - 8 Living Science Biology Ratna Sagar Solutions
Class - 8 Around the World Geography Solutions
Class - 8 Veena Bhargava Geography Solutions
Class - 8 Effective History & Civics Solutions
Class - 8 Kips Logix Computers Solutions
Class - 9 Concise Physics Selina Solutions
Class - 9 Concise Chemistry Selina Solutions
Class - 9 Dalal Simplified ICSE Chemistry Solutions
Class - 9 Concise Biology Selina Solutions
Class - 9 Total Geography Morning Star Solutions
Class - 9 Veena Bhargava Geography Solutions
Class - 9 Total History & Civics Solutions
Class - 9 Kips Logix Computers Solutions
Class - 10 Concise Physics Selina Solutions
Class - 10 Concise Chemistry Selina Solutions
Class - 10 Dalal Simplified ICSE Chemistry Solutions
Class - 10 Concise Biology Selina Solutions
Class - 10 Total Geography Morning Star Solutions
Class - 10 Veena Bhargava Geography Solutions
Class - 10 Total History & Civics Solutions
Class - 10 Sumita Arora ICSE Computers Solutions
Class - 10 Kips Logix Computers Solutions
ICSE/ISC SOLVED QUESTION PAPERS
ICSE Class 10 Computers Solved 10 Yrs Question Papers
Sample Papers ICSE Class 10 Computer Applications
ICSE Class 10 Physics Solved 10 Yrs Question Papers
Sample Papers ICSE Class 10 Physics
ICSE Class 10 Chemistry Solved 10 Yrs Question Papers
Sample Papers ICSE Class 10 Chemistry
ICSE Class 10 Biology Solved 10 Yrs Question Papers
Sample Papers ICSE Class 10 Biology
Class - 12 ISC Computer Science Solved Practical Papers
Class - 10 CBSE Computer Applications Solved Question Papers
Class - 10 CBSE Computer Applications Solved Sample Papers
Class - 10 CBSE Science Solved Question Papers
Class - 12 CBSE Computer Science Solved Question Papers
STUDYLIST
Java Pattern Programs
Java Series Programs
Java Number Programs (ICSE Classes 9 / 10)
Java Number Programs (ISC Classes 11 / 12)
Output Questions for Class 10 ICSE Computer Applications
Algorithms & Flowcharts for ICSE Computers
ICSE Class 8 Computers Differentiate Between the Following
CBSE TEXTBOOK SOLUTIONS
Class - 8 NCERT Science Solutions
Class - 9 NCERT Mathematics Solutions
Class - 9 NCERT Science Solutions
Class - 9 NCERT Geography Contemporary India 1 Solutions
Class - 9 NCERT History India & Contemporary World 1 Solutions
Class - 9 Sumita Arora Computer Code 165 Solutions
Class - 9 Kips Cyber Beans Computer Code 165 Solutions
Class - 10 NCERT Mathematics Solutions
Class - 10 NCERT Science Solutions
Class - 10 NCERT Geography Contemporary India 2 Solutions
Class - 10 NCERT History India & Contemporary World 2 Solutions
Class - 10 NCERT Democratic Politics 2 (Civics) Solutions
Class - 10 NCERT Economic Development Solutions
Class - 10 Sumita Arora Computer Code 165 Solutions
Class - 10 Kips Cyber Beans Computer Code 165 Solutions
Class - 11 CBSE Sumita Arora Python Solutions
Class - 11 CBSE Informatics Practices Preeti Arora Solutions
Class - 12 CBSE Sumita Arora Python Solutions
Class - 12 CBSE Preeti Arora Python Solutions
Class - 12 NCERT Computer Science Solutions
Class - 12 CBSE Informatics Practices Sumita Arora Solutions
Class - 12 CBSE Informatics Practices Preeti Arora Solutions
COMPANY
Pricing
About Us
Contact Us
Privacy Policy
Terms of Service
Copyright © KnowledgeBoat 2024
CBSE/ICSE Computer Applications BlueJ textbook solutions, doubts clearing with video explanations & practice tests for all subjects
Terms & conditions
This offer is valid until stocks last or till the offer ends. Final Price is inclusive of the offer. Offer is applicable on select products and brands. In the event the user returns any/all products in the order placed during the Offer Period, thereby not maintaining the minimum purchase value, as required to avail the Offer, he/she shall not be eligible for the Offer. Accordingly, the amount availed as a discount under the Offer shall stand deducted from any refund(s) processed for the returned product(s).
Related Class Are free
Aman Sir
Chemical Reaction class 10
33.State the type of chemical reactions and chemical equations that take place in the following:(i) Magnesium wire is burnt in air.(ii) Electric current is passed throug...
Aman Sir
Chemical Reactions and Equations Class 10 Important Questions with Answers Science Chapter 1
September 5 by Aks tutorial from Aman sir
We have given these Important Questions for Class 10 Science...
Notify Website Owner