Observe the picture

You may be aware of the fact that all planets move around the sun. Can you explain what the teacher said on the basis of the motion of planets? Discuss it on the basis of the following indicators.

• Which are the motions of the earth you are familiar with?

Rotation and Revolution. Earth rotates on its axis as well as revolves around the sun.

• Which are the motions of the earth you are familiar with? Which are the object that move along with the earth when it moves?

Along with the revolution of the earth around the sun, the objects on the earth are also revolving around the sun.

• Can you be in a state of rest at least for a second?

No. We can not be in a state of rest at least for a second.

What a speed! The Earth about its axis at an approximate speed 1607 kilometre per hour at the equatorial region .it revolves around the sun with a speed of 1,06,000 kilometre per hour .How wonderful it is to realise that we are moving at a great speed even while sitting still at a place.

Motion within the body

• Place your ears close to your friend’s chest. What do you experience?

We hear sound .

• what is the reason behind the sound you hear?

Heart beat is the reason behind this sound.

• What are the movement that occur within your body.

• blood circulation • motion of muscles • nerve movements • heart beats

Motion around us

• wave a piece of paper.Don’t you Don’t you feel the motion of air ?

• What are the other instances when you have experienced the motion of air ?

• While sitting on a sea shore • While traveling in a bus • During the time of breathing • While inflating a balloon

• What are the other type of motion take place around you. Enlist.

• Motion of vehicles. • Fight of aeroplane. • Motion of human being . • Fight of bird • Motion of trees • Motion of pendulum • Fan rotates

Force and motion

• When does a body start moving?

When force applies on a body, it starts moving.

• You might have seen different types of motion,either fast or slow .what is the reason for the difference?

Due to the difference in applied force. conduct the following activities.

• When did the marble, which was at rest, start moving?

Apply force using a finger.

• When did it come to rest?

Apply force by blocking it with our hand.

• When did it change its direction of motion?

Apply force by holding a scale in its path.

• When did the speed of the rolling marble increase?

Force applies by rolling another marble in the same direction at greater speed

Force and Motion We can move objects at rest by applying force. We can also change the state of motion of a body to a state of rest by applying force. We apply force to change the direction of motion or to increase or decrease the speed of motion.

Different type of motion

• Sharpen a pencil with a sharpener. • Draw a circle with a pencil fixed in a compass. • Draw a straight line using a pencil and a scale

How was the motion of the pencil in each case?

• Pencil rotate. • Pencil moves in a circular path. • Pencil moves in a straight line.

• What change in motion was brought about by applying force in each situation ? Write them down in the Science Diary.?

• The marble which was at rest was set into motion. • Change the state of motion of the marble to a state of rest. • Change the direction of motion of the marble. • Change the speed of motion of the marble.

• We watch and play games with a ball. what are the purposes for which players apply force on a ball.

• to move the ball at rest. • to stop the ball in motion. • to change the direction of motion. • to increase the speed of motion.

Group the similer ones. Add more examples to each group and write them down in the science diary.

Those resembling the action of sharpening the pencil using a sharpener Those resembling the action of drawing a circle using pencil fitted in a compass Those resembling the action of drawing a straight line using pencil and scale.
Rotation of a top Swirling a stone tied to a rope Ripe mango falling down
Rotation of the wheel of vehicles. Toy train running along a circular path? Lift going up
Rotation of spheres Motion of a chils or a merry-go-round Motion of the needle of sewing machine.
Motion of axis of a moving fan. Moon revolving round the earth. Water falls drop from the tap.
Rotatin of the central pin of a clock to which its hands are attaced Playing children in a circular manner. Bullet from gun
Motion of the key of toys motion of an oxe around an oil-press.

What is the common feature of the motion in each group?

  1. Remain standing at one place and ground.
  2. Moving around a circular path.
  3. Objects moving along a straight line.

How do groups one and two differ?

Object in group one and two are moving in a circular path. In first group objects spin on a point or axis.In the second group objects move along a circular motion.

The motion of a body along a straight line is linear motion. The movement
of a body about its own axis is rotation. The motion along a circular path is
circular motion.

Motion like this too;

You may be familiar with the following type of motions. • motion of the pendulum of a clock.
• motion of a swing.
• motion of a hanging lamp

What are the peculiarities of these movements?

• The two and motion of an object in the same path.

Find out similar examples of motions?

• Motion of a cradle. • Motion of a moving chair. • The movement of thew swing doll.

The to and fro motion of a body about a mean position is called oscillation.

What is your response to Haseeb’s query? Discuss the using the indicators given bellow.

Is it a motion about a mean position?

Yes

Does it moves to both sides?

Yes

Oscillations like this too;

Do the following activities.

• Beat one of the prongs of a tuning fork with a rubber
hammer.
• Tap on a stretched rubber band using a finger. • Place a metal scale on a table in such a way that one of its ends projects out, and tap this end using your fingers

Did you notice that these oscillations are at a greater speed?

Yes

Fast oscillations are referred to as vibrations

Vibratory motion or vibrations are oscillatory motions which are very fast to begin with and soon slow down and come to rest.

Vibrations

Let’s make a blow pipe ‘peepi’ which helps us to observe vibrations. Materials required: 10 cm long pipe of one inch diameter, a balloon, the empty case of a pen, rubber band, 2 m long thread and cello tape. Method: Cut open the closed end of the balloon. Insert the pipe at one end of the balloon and the empty case of a pen at the other. Tie them strongly using a rubber band. Hold the pipe vertically and stretch the empty pen horizontally. Now the balloon will appear like a stretched membrane. In the middle of this stretched portion fix one end of the thread using cello tape. The ‘peepi’ is now ready for use.

Motion of application

Observe a tailor stitching clothes using a sewing machine. Of the different types of motion you have already come across, which are the ones you can see in a sewing machine?

• Liner motion • Rotation • Circular motion • Oscillations.

Complete the table adding the types of motion and the uses of the instruments mentioned below.

Body in motion Type of motion Use
The membrane of a ‘chenda’ (drumhead) Oscillation Produces sound
A rotating chair Oscillation Convenence to move
The tip of a clok’s hand Circular motion Helps to know time.
The small wheel of a sewing mechine Rotation Sewing become easy.
A lift Liner motion Easily moving up and down
A swing Oscillation swing is possible.
The string of a veena Vibration Produces sound.
Wheels of a flourmill Rotation Grains become powder.

Let’s rotate the fan

Turn the rib to completely wind the thread around it. Now pull out the free
end of the thread. Don’t you see it rotating?

How did the motion of the thread pass to the leaf of the fan?

The motion of the thread pass to the leaf through the rib.

What are the devices you have seen, in which the force applied on one
part is transferred to another part and used for motion?

Cycle, sewing machine , wind mill, flour mill etc

What are the arrangements made in such devices?

Chain wheel and axie,belt etc.are the arrangements made in such devices.

Where do we apply force while cycling?

While cycle we apply force on the pedel. Through a chain this force reach the wheel.

How does this force reach the wheel?

Through a chain this force reach the wheel.

Which part is set to motion first while working a flour mill?

While working a flour mill wheel is set to motion first.

How is this rotation transferred to other parts?

Through belts these rotation transferred to other parts.

What arrangements are made use of in a sewing machine, to transfer the force applied on the pedal to the needle?

The force applied on the peddal of a sewing machine rotates the wheel connected to it. The upper and lower wheel of sewing machine is connected through a belt. As a result of the rotation of lower wheel, the upper wheel rotates. Thus the sewing becomes easy.

Can you design and construct some tools which make use of various types of movements? Write a note if it in your science diary. write below the names of the pieces of equipment you have constructed exhibit them in your science club

Thulathekku: A long stick is tied to a post which acts as the fulcrum. A bucket is tied to the longer part of the stick and a weight is attached to the shorter part.The bucket is pulled down to the well.When it gets filled with water we release our hands.Then due to the weight at the other end the bucket with water rises up.When it reaches the top of the well it is poured into the channels.

Archimede’s screw: A long wooden tube is placed in water is a slanding position so that a part of it is dipped in water. This rotates on an axis.When the axis is rotated by hand water enter the wooden tube through the space between the screw and slowly rises up and flows out through the other end of the tube.

The force applied on a machine can be transferred to other parts of the machine or to other machines thus setting them into motion. We make use of the chain, wheel and axle, belt, etc., for this purpose.

Gears

As shown in the picture, fix two corrugated plastic lids of different sizes on a wooden plank in such a way that they touch each other closely. Now turn each lid. What do you observe?

Other lid also rotates.

When the small lid is turned to the left, in which direction does the big lid turn?

Big id turned towards right.

what happens when it is turned to the right?

Big lid turned towards left.

Does the big lid also complete one rotation when the small lid completes one?

No

How many times does the small lid rotate .when the big lid is rotated once?

More than one times. it is the interlocking of corrugation on the lids that enables one to rotate with the other .Such wheels are called gears. Gear transforms rotating motion from one part of the machine to another.

Do all the gears move at the same speed? What may be the reason?Discuss.

The speed of all the gears are not the same and it depends on its number of teeth .If the number of teeth is more the speed is less and vise versa. for example gear A has 40 teeth and B has 20 teeth and C has 10 teeth .if A rotates one time, B rotates 2 time and C rotates 4 time.

How shall we arrange gears to reduce the speed of rotation ? Show it with the help of a diagram. *If the rotation of the gears is in the descending order of their teeth .its speed rotation can be reduced.

if the rotation is in the ascending order f their teeth its speed of rotation can be reduced.

were have you seen gears.

• Gears of vehicles • Flour mill Clock • Grama phone • Rubber roller • Watch • Printing press • Sugar cane crusting machine • Cycle

Do they bring about change in the direction of motion and speed of motion ?

The use of gears can bring about changes in speeds and direction of motion . When large gear drives small gear an increase in rotational speed is obtained .When small gear driving large gear reduction in rotational speed is obtained For example , the speed of an electric motor is very high to be used a machine without reduction. By making use of the rotation of one part of a machine , gears help us set in motion more than one part of a machine at different speed and in different direction. When a big wheel is turned using a small wheel ,the speed of rotation decreases when it is reversed ,the speed increases . The use of gears can bring about changes in speed and direction of motion . We make use of this advantage in a number of machines.

Let us assess

A man pulling a hand cart applies force on it in the following situations.
What is the purpose in each case? what are the changes force can bring about in the motion? 1. when he starts pulling the hand cart.?

From moving hand cart.

2. when it goes on a down hill

To decrease the speed of the hand cart

3. Change in movement caused by the force.

• A body at rest can be moved • The direction of a moving body can be changed • Increase the speed of a moving body

4 .The table on oscillation prepare by lathika,iqbal,sonu

Lathika Iqbal Sonu
The motion of the membrane across the drum head of a chenda, on beating it The motion of the membrane across the drum head of a chenda, on beating it. The motion of an arrow, shot from a bow
The motion of a swinging cot The motion of the string while playing veena The motion of the prongs of an excited tuning fork
The motion of a giant wheel The motion of the prongs of an excited tuning fork The motion of a stretched metal wire on strumming it

5. Whose finding are correct

Iqbal findings are correct

6. Which are the ones that cannot be considered as examples of oscillation?

The motion of giant wheel , the motion of an arrow

7. What is the difference between vibration and oscillation?

The to and fro motion of a body about a mean position is called oscillation . Fast oscillations are referred to as vibrations.

Observe the arrangement of gears in in the figure.

When the first gear is rotated, which other gear would also rotate in the same direction?

When the first gear is rotated , third gear also rotates in the same direction.

Which gear would be the slowest?

Fourth gear would be the slowest.

Complete the following suitably

Take a 50 cm long string and let it pass through a 25 cm long PVC pipe. Tie to one end of the string an iron nut and to the other end a bottle filled with water. Holding the pipe tightly, swirl the nut. What are the motions that you observe in the nut, the rope and the bottle?

Iron nut – Rotatior String – Vibration Bottle – Cultural motion

More Question & Answer

  1. If we view from ……….. we can see the motion of the object on the earth .

Outer space

2. Approximate speed of rotation of the earth .

1667 km/hr

3. Earth revolves around the sun with a speed of…………,

1,06,000km/hr

4. An example for the movements of occur within our body .

blood circulation.

5. ……… is the motion of the earth

wind

6. Motion of swing is an example for…..

Oscillatory motion.

7. An example for rotatory motion.

Motion of top

8. An example for periodic motion

Heart beat

9. An example for non- liner motion.

The motion of a falling leaf

10. Fast oscillations are referred to as ……….

Vibrations.

11. What type of motion does the pulley experience when we draw water using it ?

Rotatory motion

12. The motion of dripping rain drops.

Liner motion.

13. When the number of teeth of gear increased the speed of rotation……..

Decreases

14. An equipment which make use of the benefit of gears.

Cycle

15. …… work using the power of wind.

Wind mills.

Find the relation

A B C
Motion of wiper Motion of the axis of a fan Increases the speed of the object
Running around a circle Motion of the pendulam Oscilation
Motion of a top The motion of a stone when it is tied to a string Circular motion
Force Stop a moving body Rotatory motion

Answer

A B C
Motion of wiper Motion of the pendulam Oscilation
Running around a circle The motion of a stone when it is tied to a string Circular motion
Motion of a top Motion of axis a fan Rotatory motion
Force Stop a moving body Increases the speed of the object

Answer the following question.

  1. Haven’t you played a football? what type of motion does a rolling ball experience when we play football?

Liner motion

2. When we draw water using a pulley, its motion is rotatory ,isn’t it? find out the other motion like this.

Rotation of top, rotation of the fan, spinning of coin, motion of water wheel, motion of the wheel of vehicle.

3. Don’t you like swing on a swing? What type of motion is seen in the swing?

The swing moves to and fro repeatedly in the same path . This type of motion is known as oscillation.

4. Day and night caused due to the motion of the earth .What type of motion of the earth does it represent?

Rotation of the earth.

5. Note the following motions. find out circular motion and non- liner motion from this and make a table

Motion of calotropics , creeping of a snake,movement of foot in cycling,dropping of leaves , the motion of a stone when it is tied to a string and rotated, beetles fly around the flowers , throwing of stone ,flying of a butterfly

Circular motio Non- liner motion
Beetles fly around Motion of calotropis the flowers
Movement of foot in cycling Flying of a buttrfly
The motion of a stone when it is tied to a string and rotated Throwing of a stone
Dropping of leaves
Creeping of snake

6. Categorize the following into rotation ,oscillation,liner motion and periodic motion.

Spinning of a top,motion of swing ,motion of the pedal of cycle,motion of the wheel of sewing machine ,motion of the pulley ,total motion of cycle , spinning of a coin , motion of celestial bodies , motion of pendulum ,dripping rain water

Rotation oscillation lLiner motion Periodic motion
Spinning of a top motion of swing total motion of cycle motion of celestial bodies
spinning of a coin dripping rain water motion of pendulum
motion of the wheel of sewing machine
motion of the pulley

7. Write down the type of motion during the following situations. • Cycle is put on stand and its pedal is rotated • Pushing the cycle and walking • Riding on a cycle • Tailor working on a sewing machine.

Cycle put on stand and its pedal is rotated : Motion of pedal – Rotatory motion Motion of wheel – Rotatory motion

Pushing the cycle and walking : Motion of pedal – Rotatory motion Motion of wheel – Rotatory motion , periodic motion ,liner motion and curvilinear motion Total movement of the Cycle – Liner/non – liner motion

Riding on a cycle : Motion of pedal – Rotatory motion Motion of wheel – Rotatory motion ,periodic motion, liner motion ,curvilinear motion Total motion of cycle – Liner motion/ curvilinear motion

Tailor working on a sewing machine: Motion of needle – Liner motion , periodic motion Motion of the wheel – Rotatory motion Motion of pedal – Oscillation, periodic motion Motion of thread – Rotation , curvilinear motion

8. How to rotatory motion differ from circular motion? Give example of both.

• The spinning of an object around a central point is known as rotation. Example Rotation of top Rotation of the earth .

9. What are the changes taking place when force is applied on a body ?

• A body at rest can be moved • Shape of a body can be changed • The direction of a moving body can be changed • A moving body can be stopped

10. How shall we arrange gears to reduce and increase the speed of rotation ?

The rotation of the gears is in the descending order of their teeth, its speed of rotation can be reduced and if the rotation is in the ascending order of their teeth is speed of rotation can be increased.

11. Writing the working of wind mill.

The wind mill works using the power of wind .They are erected in open spaces. The fan like structure is fitted at the top of the high power .When wind blows the sails of the structure rotates on a central shaft which is connected to a pump which pumps water. Electricity can be produced by connecting the start to ma generator.

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