Question 1:
Identify the types of motion.
(a) Movement of the earth around the sun : .......... .
(b) Movement of a ceiling fan : ..........
(c) A meteor falling from the sky : .......... .
(d) A rocket launched from the ground : ..........
(e) A fish swimming in water : ..........
(f) The plucked string of a sitar : .......
ANSWER:
(a) Movement of the earth around the sun : Circular and periodic motion.
(b) Movement of a ceiling fan : Circular motion.
(c) A meteor falling from the sky : Non-uniform linear motion.
(d) A rocket launched from the ground : Non-uniform linear motion.
(e) A fish swimming in water : Random motion.
(f) The plucked string of a sitar : Oscillatory motion
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Question 2:
Fill in the blanks.
(a) If a ball is released from the terrace of a building, it comes down in ........... motion. On the other hand, it reaches the ground in ........... motion if it is thrown with force away from the terrace in a direction parallel to the terrace.
(b) The motion of an aeroplane on the runway before take-off is.......... .
(c) The kite looking for its prey flies with .......... motion in the sky.
(d) Children sitting in a rotating giant wheel have ........... motion, while those sitting in a merry-go-round have a ........... motion.
(Linear, non-linear, circular, uniform linear, non-uniform linear, uniform circular, non-uniform circular, random)
ANSWER:
(a) If a ball is released from the terrace of a building, it comes down in non-uniform linear motion. On the other hand, it reaches the ground in non-linear motion if it is thrown with force away from the terrace in a direction parallel to the terrace.
(b) The motion of an aeroplane on the runway before take-off is non-uniform linear motion .
(c) The kite looking for its prey flies with random motion in the sky.
(d) Children sitting in a rotating giant wheel have non-uniform circular motion, while those sitting in a merry-go-round have a uniform circular motion.
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Question 3:
How are we different?
(a) Oscillatory motion and linear motion.
(b) Linear motion and random motion.
(c) Random motion and oscillatory motion.
ANSWER:
(a)
| Oscillatory motion | Linear motion |
| The type of motion in which the object moves back and forth repeatedly is known as oscillatory motion. | The type of motion in which the object moves from one point to another in a straight line is called linear motion. |
| For example: Movement of the pendulum of a clock | For example: Vehicles moving on a straight road |
(b)
| Linear motion | Random motion |
| The type of motion in which the object moves from one point to another in a straight line is called linear motion. | The type of motion in which the direction of motion and the speed of an object changes continuously is called random motion. |
| For example: Vehicles moving on a straight road | For example: Children playing in a garden |
(c)
| Random motion | Oscillatory motion |
| The type of motion in which the direction of motion and the speed of an object changes continuously is called random motion. | The type of motion in which the object moves to and fro repeatedly about a mean or a fixed position is known as oscillatory motion. |
| For example: Children playing in a garden | For example: Movement of the pendulum of a clock |
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Question 4:
Explain in your own words, giving one example each.
(a) Linear motion
(b) Oscillatory motion
(c) Circular motion
(d) Random motion
(e) Periodic motion
ANSWER:
(a) Linear motion: An object is said to have linear motion if it moves from one point to another in a straight line. For example: The motion of a moving car on a straight road.
(b) Oscillatory motion: The type of motion in which the object moves to and fro repeatedly about a mean or a fixed position is known as oscillatory motion. For example: The movement of pendulum of a clock.
(c) Circular motion: An object is said to possess circular motion if it moves from one point to another in such a way that its distance from a fixed point always remains constant. For example: The movement of the blades of a fan.
(d) Random motion: The type of motion in which the direction of motion and the speed of an object changes continuously is called random motion. For example: Children playing in a garden.
(e) Periodic motion: An object is said to possess periodic motion if it moves in such a way that it repeats its motion after a certain interval of time. For example: The motion of a swing.
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Question 5:
Answer the following questions in your own words.
(a) Which types of motion are seen in birds flying in the sky ?
(b) Write in detail about your experience of various types of motion while riding a bicycle on a road.
ANSWER:
(a) Birds flying in the sky have random motion as their direction of motion and speed continuously changes.
(b) While riding a bicycle on a road, following types of motion can be seen:
- The wheels of the bicycle are in uniform or non-uniform circular.
- The legs of the person riding the bicycle are in uniform or non-uniform circular motion.
- The bicycle is in uniform or non-uniform linear motion. It can also be in non-uniform motion.
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Question 6:
Complete the puzzle using words for types of motion :
(1) a spring is stretched and one end is released
(2) a minute hand
(3) a see saw
(4-5) children in a march past
(6) a stone rolling down a hillside..png)
ANSWER:
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