Light And Shadows - SAP Education

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P3/4 science

1. Which of the following graphs shows the length of the lamp-post’s shadow from 9 am to 5pm?

(1) Length of shadow (cm)

9 am 5 pm


9 am 5 pm


9 am 5 pm


9 am 5 pm ( )

2. Rudolf is walking from points D to A.

Which one of the following shows the correct order of the length of Rudolf’s shadows from the longest to the shortest when he walks from point D to point A?

(1) A, B, D, C (3) C, B, A, D(2) D, A, B, C (4) A, D, B, C ( )

lamp-post

Light And Shadows

A B C D

Rudolflamp

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Taken from NaiL thoSe McQs! PriMary ScieNce LoWer BLock 3/4


P3/4 science

3. Look at the diagram below.

Whichoneofthefollowingshowsthecorrectreflectionofthepicturecardonthemirror?

(1) (3)

(2) (4)

( )

mirror picture card

Light And Shadows

Answers: 1. 4 2. 2 3. 4


Taken from NaiL thoSe McQs! PriMary ScieNce LoWer BLock 3/4


P3/4 science

1. Mrs Smith is standing at the doorway of the classroom. She is unable to see Joe no matterwhich direction she looks.

(a) What does this tell us about the behaviour of light? [1m]

(b) However, from inside the classroom, Mrs Smith can hear the music blaring from Joe’sMP3 player.

What does this tell us about the behaviour of sound? [1m]

(c) In the space below, describe and draw the set-up of a simple experiment which canillustrate the characteristic behaviour of light as mentioned in (a). You may draw adiagram to aid your description. [5m]

Mrs SmithJoe

MP3 player

Light and Shadows


Taken from ScieNce ProceSS SkiLLS LoWer BLock 3/4


P3/4 science

1. (a) Light travels in straight lines and cannot pass through opaque objects.1. (b) Sound waves can travel through solids.1. (c) Set up the experiment as shown below:

eye

opaque cardboardhole cut into cardboard

lighted candle

When the holes on the three sheets of cardboard are aligned, the eye can see the candle flame.However,ifonesheetofcardboardispushedoutofplacesuchthattheholesareno longer in alignment, the opaque cardboard blocks the path of the light ray and the flamecannotbeseen.

Answers To Light and Shadows

Taken from ScieNce ProceSS SkiLLS LoWer BLock 3/4SAPSCSP3&4_W35

Page 4/6


P3/4 science

1. When an ordinary drinking draw is placed in a glass of plain water, the straw appears bentwhen viewed from the side of the glass. [3m]

How is this possible?

plain water in glass

drinking straw

Light and Shadows

Answers: 1. Light travels faster in air than in water. The change in speed of the light rays as it passes the air-water boundary causes the straw to appear bent although it is actually straight.




P3/4 science

1. (a) Studytheflowchartbelow.Fillintheboxeswiththecorrectclassofmaterial. [1m]

(b) Describe the shadow formed by material (iii). [1m]

(c) Compare materials (i), (ii) and (iii) in terms of the amount of light that passes througheach of them. [1m]

Material

Does it allow the formation of a shadow?

Is the shadow formed light and blurred?

(i)

(ii)

No

Yes

No

Yes

(iii)

Light and Shadows

Answers: 1. (a) (i) transparent material (ii) translucent material (iii) opaque material 1. (b) The shadow is dark and clear. 1. (c) Material (i) allows all light to pass through it completely. Material (ii) allows some light to pass through it. Material (iii) does not allow any light to pass through it at all.



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Light And Shadows - SAP Education