
- •The frequency decreases by increasing Periodic time.
- •9 The intensity of sound is measured by unit ……… .
- •Calculate frequency of savart wheel rotates by 300 cycle/minute when it touches a gear of 120 teeths.
- •2) Calculate the number of cycles in savart wheel produces 500 cycle/sec. If the number of teeths is 25 teethes.
- •1) Calculate the depth of sea when waves are sent with velocity 1490 m/sec and time of reflection is 0.1 sec.
- •1 ) Label the figure.
1) Calculate the depth of sea when waves are sent with velocity 1490 m/sec and time of reflection is 0.1 sec.
………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………
2) A person stands between two mountains then he made a sound he heard two echoes. The first after 1.4 seconds and the second after 1 second from the first echo. Calculate the distance between him and each mountain taken that speed of sound in air 340 m/sec.
Because they produce ultrasonic waves determine places of things in front of them.
………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………
Because they have concave surfaces that collect sound and concentrate it.
N
ature
of light waves
work
sheet five
Question One: Complete the following:
1- Light is considered as ………. waves. Their wave length ranges between ………. : ………. Nanometer.
2- ………. is the distance travelled by light in one second.
3- The white light consists of ………. colours started with ………. and ended by ………. .
4- Energy of light quantum = ……… × frequency.
5- Increasing the thickness of medium decreasing the ……… of light through it.
6- The light propagates in air as ………lines.
7- Light intensity is the amount of light that falls ……… on the unit area in one second.
8- Light intensity ……… proportional with square of distance between surface and ………
9- Air is ……… medium, while milk is ………
10- We can use ……… to analyze light.
Question Two: Give Reasons for:
1- The energy of red light is smaller than orange colour.
………………………………………………………………………………………………………………………………B
2- We can’t see impurities in black honey. ………………………………………………………………………………………………………………………………
3- Energy of light quantum depends on its frequency.
………………………………………………………………………………………………………………………………
4- Light intensity is inversely proportional with square of distance. ………………………………………………………………………………………………………………………………
Question Three:Write the scientific term:
1- Electromagnetic waves travel in straight lines. ……………………………….
2- Dispersing white light into seven colours. ……………………………….
3- Instruments used to analyze white light. ……………………………….
4- The colour of lowest frequency. ……………………………….
5- The scientist who proved that light consists of quantum of light. ……………………………….
6- A medium that doesn’t allow light to pass through…………………………
7- The amount of light that falls perpendicular on the unit area in one second. ……………………………….
8- The light intensity is inversely proportional with square of distance between surface and source of light. ……………………………….
W ork sheet six Reflection and refraction of light
Question One: Complete the following:
1- The rebounding of light rays back to the source is called ……… of light.
2- The reflection of light can be divided into ……… or ……… .
3- When the light falls on rough surface it is called ……… reflection.
4- Angle of incidence = ……… .
5- If the light ray falls ……… it reflects on itself where angle of ……… =……… equal zero.
6- The ……… instrument is used in submarines.
7- The light ……… are used in medical ……… to make operations without surgery.
8- The ability of medium to refract light is called ……… .
Question Two: Give reasons for:
1- Occurrence of Mirage. ………………………………………………………………………………………………………………………………..
2- The perpendicular light ray reflects on itself. ………………………………………………………………………………………………………………………………..
3- Objects are seen some times upnormal. ……………………………………………………………………………………………………………………………
4- The bottom of swimming pool is seen higher than its real place.
… ……………………………………………………………………………………………………………………………..5- The refractive index is greater than (1).
………………….…………………………………………………………………………………………………………..6- Occurrence of light refraction.
………………………………………………………………………………………………………………………………..Question Three: Write the scientific term:
1- The rebounding of light waves on falling on a reflecting surface.
……………………..
2- The reflection of light rays in one direction on falling on smooth surface. …………………………..
3- The reflection of light rays in different directions from rough surface. …………………………..
4- Angle of incidence = angle of reflection. ……………………………..
5- Instrument used in submarines to see under water………………………
6- The angle between refractive ray and perpendicular line………………
7- The change of light direction on transferring from transparent medium to another. …… …………………
8- The relation between light velocity in air and light velocity in medium. ……………………………
9- The angle when the incident angle in the medium of lowest density = 90ْ …………………………….
Q uestion Four: What is meant by?
1- Refractive index of water is 1.3
…………………………………………………………………………………………………………………………….
2- Seeing objects upside dwon in desert at noon time.
…………………………………………………………………………………………………..
3- Light reflects on itself.
……………………………………………………………………………………………………………………………. Question Five:Problems:
Calculate the refractive index of diamond if the light velocity in it is 1.25 × 108 m/sec
…………………………………………………………………………………………………………………………….…………………………………………………………………………………………………………………………….
Work sheet seven Reproduction in flowering plants
Q uestion One: Complete the following:
1- The flower grows on ……… bud on the ……… .
2- The male organ in flower is ……… while the female organ is ………
3- The male flower has ……… whorls which are ………, ……… and ……… .
4- The stamen consists of ……… ended by ……… .
5- The pistil in flower consists of ………, style and ……… .
6- The anther consists of ……… sacs contain ……… .
7- Pollination is done by transferring ……… from ……… to ……… .
8- Pollination in large coloured flowers is done by ……… .
9- The flower that has four whorls is called ……… and its sex is …
10- As an example for unisexual flower is ……… .
11- The flower is the ……… organ in plant.
12- The pollination in the same flower is ……… .
13- If the ovary contains many ovums it forms ……… seeds as in ……… plant.
14- A sexual reproduction in plants is divided into ……… and ………
Question Two: Write the scientific term:
1- The reproductive system in flowering plants. ………………………………….
2- The complete flower. ………………………………….
3 - Male reproductive organs in flower. …….………………………
4- Female reproductive organs in flower. ………………………………….
5- Transfer of pollen grains from anther to stigma. ……………………………
6- Green colored leaves surround the flower. ………………………………….
7- Swollen part hold the flower parts. ………………………………….
8- Reproduction by green parts in flower. ………………………………….
9- Male cells spread in air. ………………………………….
10- The cell formed from combination of male cell with female cell. ……………………………….
11- The flower that contains pistil and stamen. ………………………………….
Question Three: Give reasons for:
1- Palm trees are unisexual flower. ………………………………………………………………………………………………………………………………
2- Sun plant is not having self pollination. ……………………………………………………………………………………………………………………………… 3- Stigma of flowers is sticky. To stick with pollen grains. ……………………………………………………………………………………………………………………………… 4- Flowers have coloured petals. ………………………………………………………………………………………………………………………………
5- Onion flower is typical bisexual flower. ………………………………………………………………………………………………………………………………
6- Bees have important for plants. ……………………………………………………………………………………………………………………………… i
7
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Some flowers are hanged in air anthers..
……………………………………………………………………………………………………………………………… 8- Olive plant contains one seed. ………………………………………………………………………………………………………………………………
9- Man makes pollination in some plants. ………………………………………………………………………………………………………………………………
To produce important crops as date in palm
Question Four: Study the following figure then answer: