Force and Motion Book Back Questions 6th Science Lesson 2

6th Science Lesson 2

2] Force and Motion

Book Back Questions with Answer and Do You Know Box Content

Do you know?

Aryabatta, an ancient Indian astronomer, said, “As the banks of the river appear to move back to a person in a boat floating gently in a river, the night sky studded with stars appear to move from the east to the west and so the Earth rotates from the west to the east.”

Forces are push or pull by an animate or inanimate agency.

Oscillations at Greater Speed: Ask your friend to hold the two ends of a stretched rubber band. Strike it in the middle. Do you see that it oscillates very fast? When the oscillation is very swift, it is called as vibration. Fast oscillations are referred to as vibrations.

All oscillatory motions are periodic, but not all periodic motions are oscillatory motion.

The distance travelled by an object in unit time is called speed of the object. If an object travelled a distance “d” in time “t” then, its speed is given as:

Speed (s) = Distance travelled / Time taken = d / t

Usain Bolt crossed 100 metre in 9.58 seconds and made a world record. If you are able to run faster than him, then Olympic Gold Medal is waiting for you.

A Cheetah is the fastest land animal running at a speed of 112 km/h.

Choose the correct answer:

1. Unit of Speed is

(a) m

(b) s

(c) kg

(d) m/s

2. Which among the following is an oscillatory motion?

(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

3. The correct relation among the following is

(a) Speed = Distance x Time

(b) Speed = Distance / Time

(c) Speed = Time / Distance

(d) Speed = 1 / (Distance x Time)

4. Gita travels with her father in a 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 at a speed of 1 Km / minute.

Statement 2: She travels at a speed of 1 km/hour.

(a) Statement 1 alone is correct.

(b) Statement 2 alone is correct.

(c) Both statements are correct

(d) Neither statement 1 nor statement 2 is correct.

Fill in the blanks:

1. A bike moving on a straight road is an example for _______________ motion.

2. Gravitational force is a ______________ force.

3. Motion of a potter’s wheel is an example for ________________ motion.

4. When an object covers equal distances in equal interval of time, it is said to be in _______________ motion.

State true or false. If false, correct the statement:

1. To and fro motion is called oscillatory motion.

2. Vibratory motion and rotatory motion are periodic motions.

3. Vehicles moving with varying speeds are said to be in uniform motion.

4. Robots will replace human in future.

Match the following:

1. a. Circular motion

2. b. Oscillatory motion

3. c. Linear motion

4. d. Rotatory motion

5. e. Linear and rotator motion

Given below is the distance-travelled by an elephant across a forest with uniform speed. Complete the data of the table given below with the idea of uniform speed:

Distance (m)	0	4		12		20
Time (s)	0	2	4		8	10

Complete the analogy:

1. Kicking a ball : Contact force :: Falling of leaf : _________________?

2. Distance : metre :: Speed : ____________?

3. Circulatory motion : A spinning top :: Oscillatory motion : _____________?

Complete the web chart:

Non-periodic
	Movement repeated after a fixed interval of time	Movement about an axis or a fixed centre

Answer in a word or two:

1. The force which acts on an object without physical contact. ______________

2. A change in the position of an object with time. ________________

3. The motion which repeats itself after a fixed interval of time. _______________

4. The motion of an object which covers equal distances in equal intervals of time. ________________

5. A machine capable of carrying out a complex series of actions automatically. _______________

Answers:

Choose the correct answers:

1. s 2. To and fro movement of a vibrational string 3. Speed = Distance / Time 4. Statement 1 alone is correct

Fill in the blanks:

1. Linear 2. Non-contact force 3. Rotatory 4. Uniform

State True or False:

1. True

2. False

Correct Statement: Vibratory motion and Oscillatory motion are periodic motions.

3. False

Correct Statement: Vehicles moving with varying speed are said to be in non-uniform motion.

4. False

Correct Statement: Robots cannot replace human in future.

Match the following:

1. Linear motion 2. Rotatory motion 3. Oscillatory motion 4. Circular motion 5. Linear and Rotator motion

Given below is the distance-travelled by an elephant across a forest with uniform speed. Complete the data of the table given below with the idea of uniform speed:

Distance (m)	0	4	8	12	16	20
Time (s)	0	2	4	6	8	10

Complete the Analogy:

1. Non-contact force 2. Meter/second 3. Swinging of a pendulum

Complete the web chart:

Non-periodic	Periodic motion	Rotational motion
Movement not repeated in a uniform interval	Movement repeated after a fixed interval of time	Movement about an axis or a fixed centre

Answer in a word or two:

1. Non-contact force 2. Motion 3. Oscillatory motion 4. Uniform motion

5. Robots