Answers marked verified were checked during generation against the chapter context and source question text.
Your Progress - Chapter 20% complete
1I. Choose the Correct Answer:4 questions
Q.2Oscillatory motion among the following isv
- A. Rotation of the earth about its axis
- B. Revolution of the moon about the earth
- C. To and fro movement of a vibrating string
- D. All of these
Answer:(c) To and fro movement of a vibrating string
Q.3The correct relation among the following isv
- A. speed = distance × time
- B. Speed = distance / time,
- C. speed = time / distance
- D. Speed = 1 / (distance × time)
Answer:b. Speed = distance / time
Q.4Gita rides with her father’s bike to her uncle’s house which is 40 km away from her home. She takes 40 minutes to reach there. Statement 1 : She travels with a speed of 1 km/minute. Statement 2 : She travels with a speed of 1 km/hourv
- A. Statement 1 alone is correct.
- B. Statement 2 alone is correct.
- C. Both Statement 1 and 2 are correct.
- D. Neither statement 1 nor statement 2 is correct.
Answer:(a) Statement 1 alone is correct
2II. Find whether the following statements are true or false. – if false give the correct Answer.1 questions
Q.G1To and fro motion is called oscillatory motion. Vibratory motion and rotatory motion are periodic motions. Vehicles moving with varying speeds are said to be in uniform motion. Robots will replace human in future.v
Answer:True
True
Non-uniform.
False, Robots can never be conscious.
3III. Fill in the blanks:1 questions
Q.G2A bike moving on a straight road is an example of ……… motion. Gravitational force is a ………… force. Motion of a potter’s wheel is an example of ………… motion. When an object covers equal distances in equal interval of time, it is said to be in ……….. motion.v
Answer:Linear
non-contact
Rotatory
Uniform
4V. Analogy:1 questions
Q.G3Kicking a ball: contact force :: falling of leaf : ………… Distance : metre :: Speed : …………. circulatory motion : a spinning top oscillatory motion : …………v
Answer:non contact forces
m/s
Pendulum
5VI. Given below is the distance – travelled by an elephant across a forest with uniform speed.1 questions
Q.G4Complete the data of the table given below with the idea of uniform speed.v
6VIII. Give one word for the following statements.5 questions
Q.1The force which acts on an object without Physical contact with it.v
Answer:Non-contact force.
Q.2A change in the position of an object with time.v
Q.3The motion which repeats itself after a fixed interval of time.v
Answer:Oscillatory motion.
Q.4The motion of an object travels equal distances in equal intervals of time.v
Q.5A machine capable of carrying out a complex series of actions automatically.v
7IX. Answer the following in a sentence or two:5 questions
Q.1Define force.v
Answer:Forces are push or pull by an animate or inanimate agency.
Q.2Name different types of motion based on the path.v
Answer:Linear motion.
Curvilinear motion.
Circular motion.
Rotatory motion.
Oscillatory motion.
Zigzag (irregular) motion.
Q.3If you are sitting in a moving car will you be at rest or motion with respect to your friend sitting next to you?v
Answer:I am at rest with respect to my friend, sitting inside the car.
Q.4The rotation of the earth is a periodic motion. Justify.v
Answer:Motion repeated in equal intervals of time is called periodic motion. The earth rotates on its axis once in 24 hours. The duration of time is fixed as 24 hours. Therefore the rotation of the earth is a periodic motion.
Q.5Differentiate between rotational and curvilinear motionv
Answer:Rotational motion:
A body moves along a circular path.
Without changing its position, about its own (fixed) axis.
Eg. Rotation of a spinning top.
Curvilinear motion:
A body moves along a curved path.
Changes its position with motion.
Eg. Throwing paper airplanes or paper darts.
8X. Calculate.1 questions
Q.1A vehicle covers a distance of 400 km in 5 hours calculate its average speed.v
Answer:Average speed = \(\frac{distence}{time}\)
= \(\frac{400}{5}\) = 80 km per hour
9XI. Answer in detail:1 questions
Q.1What is motion? classify different types of motion with examples.v
Answer:Motion: The change of position of an object with respect to time is known as motion.
1. Based on Path:
Linear motion. – Ex.: Parade of the soldiers.
Curvilinear motion. – Ex.: Paper flight moving.
Circular motion. – Ex.: Swirling stone tied to the rope.
Rotatory motion. – Ex.: Rotating top.
Oscillatory motion. – Ex.: Clock pendulum.
Zigzag (irregular) motion. – Ex.: Motion of a bee.
2. Based on Duration :
Periodic motion. – Ex.: Motion of a bob of simple Pendulum.
Non-periodic motion. – Ex.: Swaying of the branches of a tree.
3. Based on Speed:
Uniform motion. – Ex.: Hour hand of a clock.
Non – uniform motion. – Ex.: Motion of a train, as it leaves a station.
10I. Choose the best option:5 questions
Q.1How earth revolves?v
- A. From west to east
- B. east to west
- C. From north to south
- D. south to west.
Answer:(a) From west to east
Q.2People walking in a crowded street is an example of _______ motion.v
- A. linear
- B. circular
- C. rotatory
- D. zigzag
Q.3What is the unit of average speed in SI system?v
- A. metre / second
- B. kilometre/ seconds
- C. kilometre/ time
- D. Metre/ Time.
Answer:(a) metre / second
Q.4Usain Bolt crossed 100 metre in _______ seconds and made a world record.v
- A. 9.58
- B. 9.83
- C. 9.85
- D. 9.38
Q.5The motion of the moon which revolves around the earth isv
- A. Oscillatory motion
- B. Periodic motion
- C. curvilinear
- D. b and c
Answer:(b) Periodic motion
11III. Fill up the blanks:1 questions
Q.G6People walking in a crowded street is ……….. type of motion. Object moves not at a constant speed then the motion is ……….. If Priya in her cycle travels 40 km in 2 hours then what is her average speed? Motion is of ………… types. The movement of a body about its own axis is ………….v
Answer:Irregular
on- uniform motion
20 km /hr
four
Rotatory motion
12V. Fill up the blanks in accordance with their relation:1 questions
Q.G7The Motion of train – uniform motion. The motion of vehicles ……….. Periodic motion – The motion of the moon revolves around the earth. Oscillatory motion ………..v
Answer:non – uniform motion.
Motion of simple pendulum.
13VIII. Two Mark Questions: Short answers:3 questions
Q.2What are the types of Force?v
Answer:Contact Force;
Non-Contact Force
Q.3List out the types of forces on the basis of contact.v
Answer:There are two types:
Contact force,
Non-contact force.
Q.5Define non-periodic motion.v
Answer:When a motion is not in uniform interval, then such motion is called non-periodic motion.
14IX. Give Detailed Answers:1 questions
Q.1What is a force? What are its types?v
Answer:Forces: Forces are push or pull by an animate or inanimate agency.
Types of Forces:
Contact forces;
Non – Contact forces.
1. Contact forces: The force that is executed by touching the body is a contact force Eg. Kicking the football
2. Non – Contact forces: The force is applied. Without touching the object then it is called noncontact force.
Forces can
(i) Change the states of the body from rest to motion or motion to rest.
(ii) Either change the speed or direction or both of the body.
(iii) Change the shape of the body.