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Unit 3 · Isi Padu Cecair dan Pepejal Tidak Sekata
Unit 3

Isi Padu Cecair dan Pepejal Tidak Sekata

Mak Su mahu membuat kek. Resipinya memerlukan 250 mℓ susu. Bagaimanakah dia menyukat susu dengan tepat?
Bagaimana pula kita mengukur isi padu batu yang bentuknya tidak sekata? Mari belajar!

液体 = cecair；不规则固体 = pepejal tidak sekata；量 = sukat Mak Su 做蛋糕要用 250 毫升牛奶，怎样才量得准？石头的形状不规则，不能用小方块装，又要怎样量它的体积？这一课学用量筒量液体、正确读凹液面，以及用排水法量不规则固体的体积。最后复习整个第六章。 例子：药水瓶附的小量杯，也是用来准确量液体的。 注意：量液体和量石头用的工具一样，都是量筒，但方法不同。
liquid = cecair; irregular solid = pepejal tidak sekata; measure out = sukat Mak Su needs 250 mℓ of milk for a cake. How can she measure it accurately? And a stone has an irregular shape, so it cannot be filled with cubes; how do we find its volume? In this unit we use a measuring cylinder for liquids, read the meniscus correctly, and use the water displacement method for irregular solids. At the end we review all of Chapter 6. Example: the little cup that comes with a bottle of medicine is also for measuring liquid accurately. Watch out: liquids and stones are both measured with a measuring cylinder, but the methods differ.
Isi padu cecair

Silinder penyukat dan bikar

Alat menyukat cecair

Silinder penyukat

tinggi dan sempit · senggatan rapat · bacaan lebih tepat

Bikar

lebar · mudah dituang · bacaan anggaran
量筒 = silinder penyukat；烧杯 = bikar；刻度 = senggatan 量液体的体积可以用量筒或烧杯。量筒又高又窄，刻度很密，所以读数比较准确；烧杯比较宽，适合装很多液体、倒来倒去，但刻度粗，只能读出大约的数字。要准确量的时候，选量筒。 例子：做实验要准确量 35 mℓ 的水，就用量筒，不用烧杯。 注意：普通的杯子没有刻度，不能用来量体积。
measuring cylinder = silinder penyukat; beaker = bikar; scale marks = senggatan The volume of a liquid can be measured with a measuring cylinder or a beaker. A measuring cylinder is tall and narrow with close scale marks, so its reading is more accurate. A beaker is wider and good for holding and pouring a lot of liquid, but its marks are spread out, so it gives only a rough reading. When accuracy matters, choose the measuring cylinder. Example: to measure exactly 35 mℓ of water for an experiment, use a measuring cylinder, not a beaker. Watch out: an ordinary cup has no scale, so it cannot measure volume.
Meniskus

Baca dengan mata yang betul

Mata separas dengan bahagian bawah meniskus

A ✗C ✗B ✓Mata separasbawah meniskus
凹液面 = meniskus；视线平齐 = mata separas；读数 = bacaan 量筒里水的表面不是平的，而是中间低、两边高的弯曲面，叫凹液面。读数要读凹液面最低的地方，眼睛也要跟它在同一个高度。动画里眼睛 A 太高、眼睛 C 太低，读到的数字都不准确；只有眼睛 B 平视，读数才正确。 例子：量的时候把量筒放在平平的桌面上，自己蹲下来，让眼睛跟水面一样高。 注意：不要读凹液面两边比较高的地方。
meniscus = meniskus; eye level = mata separas; reading = bacaan The water surface in a measuring cylinder is not flat; it curves, lower in the middle and higher at the sides. This curved surface is the meniscus. Read the scale at the bottom of the meniscus, with your eye at the same height. In the animation eye A is too high and eye C is too low, so both give an inaccurate reading; only eye B, looking straight across, gives the right reading. Example: stand the cylinder on a flat table and crouch down so your eye is level with the water. Watch out: do not read the higher edges of the meniscus.
Cuba

Berapakah isi padu air di dalam silinder penyukat ini?

3035404550mℓ
读量筒 = baca silinder penyukat 图中每一小格是 1 mℓ，40 上面第二格就是 42。凹液面最低的地方刚好在 42，所以水的体积是 42 mℓ。43 是读了两边较高的边缘；38 是往下数错了方向。 例子：凹液面最低处在 35 上面第一格，就读 36 mℓ。 注意：先看清楚一小格代表多少，再数格子。
reading a measuring cylinder = baca silinder penyukat Each small mark in the picture is 1 mℓ, so the second mark above 40 is 42. The bottom of the meniscus sits exactly on 42, so the volume of water is 42 mℓ. 43 comes from reading the higher edges, and 38 comes from counting in the wrong direction. Example: if the bottom of the meniscus is one mark above 35, the reading is 36 mℓ. Watch out: first check how much one small mark stands for, then count.
Cuba

Di manakah kedudukan mata yang betul semasa membaca isi padu air dalam silinder penyukat?

眼睛的位置 = kedudukan mata 读量筒时，眼睛要跟凹液面最低的地方在同一个高度（像动画里的眼睛 B），这样读数才准确。眼睛比凹液面高（从上面看）或比凹液面低（从下面看），视线都是斜的，读到的数字会不准确，是错误的读数。 例子：量筒放在桌上，蹲下来让眼睛跟水面一样高，再读凹液面最低处的刻度。 注意：记住“平视才准”，从上面看或从下面看都会读错。
eye position = kedudukan mata When reading a measuring cylinder, your eye must be at the same height as the bottom of the meniscus, like eye B in the animation, so the reading is accurate. If the eye is higher than the meniscus (looking from above) or lower than it (looking from below), the line of sight slants and the reading is inaccurate, so it is wrong. Example: with the cylinder on a table, crouch so your eye is level with the water, then read the mark at the bottom of the meniscus. Watch out: only eye level reads right; looking from above or from below both give a wrong reading.
Pepejal tidak sekata

Kaedah sesaran air

Isi padu air yang tersesar = isi padu objek

020406080100awal 50 mℓ020406080100akhir 65 mℓmasukkan batu65 − 50= 15 mℓ

Isi padu objek = bacaan akhir − bacaan awal

排水法 = kaedah sesaran air；最初读数 = bacaan awal；最后读数 = bacaan akhir 石头形状不规则，可以用排水法量体积。先在量筒里装水，记下最初读数 50 mℓ；用线绑住石头，慢慢放进水里，水被石头挤开，水位升到 65 mℓ，这是最后读数。石头的体积 = 65 − 50 = 15 mℓ，也就是 15 cm³。 例子：一把钥匙放进去，水从 30 mℓ 升到 34 mℓ，钥匙的体积就是 4 mℓ。 注意：石头要完全浸在水里，而且要慢慢放，免得水溅出来。
water displacement method = kaedah sesaran air; first reading = bacaan awal; final reading = bacaan akhir A stone has an irregular shape, so we find its volume by water displacement. Fill a measuring cylinder with water and record the first reading, 50 mℓ. Tie the stone to a thread and lower it gently into the water; the stone pushes the water aside and the level rises to 65 mℓ, the final reading. The stone's volume is 65 − 50 = 15 mℓ, which is 15 cm³. Example: a key lowered in makes the water rise from 30 mℓ to 34 mℓ, so the key's volume is 4 mℓ. Watch out: the stone must be fully under water, and lower it slowly so no water splashes out.
Makmal interaktif

Ukur isi padu dengan sesaran air

Pilih objek. Tekan Masukkan objek. Baca bacaan akhir dan pilih isi padu objek.

放进物体 = masukkan objek；石头 = batu；橡皮擦 = pemadam；钥匙 = kunci 实验台的量筒一开始有 50 mℓ 水。选一个物体，按 Masukkan objek，物体沉进水里，水位慢慢上升，停下来的数字就是最后读数。接着从三个答案里选出物体的体积。石头、橡皮擦、钥匙三个都要试。 例子：如果水位停在 58 mℓ，体积就是 58 − 50 = 8 mℓ。 注意：不要直接选最后读数，那是水加物体的总数，要减掉原来的 50 mℓ。
put the object in = masukkan objek; stone = batu; eraser = pemadam; key = kunci The cylinder in the lab starts with 50 mℓ of water. Pick an object and press Masukkan objek; the object sinks and the water slowly rises, and the number where it stops is the final reading. Then choose the object's volume from three answers. Try all three: the stone, the eraser and the key. Example: if the water stops at 58 mℓ, the volume is 58 − 50 = 8 mℓ. Watch out: do not pick the final reading itself; it is water plus object, so subtract the starting 50 mℓ.
Semak makmal

Bacaan awal 30 mℓ. Selepas sebiji guli dimasukkan, bacaan akhir 36 mℓ. Berapakah isi padu guli?

计算弹珠体积 = kira isi padu guli 弹珠放进去以后，水位从 30 mℓ 升到 36 mℓ，上升了 36 − 30 = 6 mℓ，所以弹珠的体积是 6 mℓ。36 是最后读数，是水和弹珠加起来；66 是把两个读数加起来，做错了运算。 例子：最初 45 mℓ、最后 52 mℓ，物体体积是 7 mℓ。 注意：排水法一定是“减”，不是“加”。
working out a marble's volume = kira isi padu guli With the marble in, the water rises from 30 mℓ to 36 mℓ, a rise of 36 − 30 = 6 mℓ, so the marble's volume is 6 mℓ. 36 is the final reading, water and marble together, and 66 comes from adding the two readings, which is the wrong operation. Example: a first reading of 45 mℓ and a final reading of 52 mℓ give an object volume of 7 mℓ. Watch out: the displacement method always subtracts; it never adds.
Tin Eureka

Untuk objek yang besar

Air yang melimpah dikumpul dan disukat

1
Isi tin Eureka sehingga air menitis dari muncung
2
Letak silinder penyukat di bawah muncung
3
Masukkan objek perlahan-lahan
4
Baca isi padu air yang terkumpul
溢水罐 = tin Eureka；出水口 = muncung；溢出 = melimpah 物体太大放不进量筒时，用溢水罐。先把溢水罐装满水，直到水开始从出水口滴出来，等它停了；在出水口下面放量筒；把物体慢慢放进罐里，被挤出来的水从出水口流进量筒。量筒里的水有多少，物体的体积就是多少。 例子：把一个挂锁放进溢水罐，流出 22 mℓ 的水，挂锁的体积就是 22 mℓ。 注意：一开始一定要装到刚好会溢出的高度，不然流出来的水会比较少。
Eureka can = tin Eureka; spout = muncung; overflow = melimpah When an object is too big for a measuring cylinder, use a Eureka can. Fill the can with water until it starts dripping from the spout, and wait until it stops. Put a measuring cylinder under the spout. Lower the object gently into the can; the water it pushes out flows from the spout into the cylinder. The volume of water collected equals the object's volume. Example: a padlock lowered into a Eureka can pushes out 22 mℓ of water, so the padlock's volume is 22 mℓ. Watch out: the can must be filled right up to the spout first, or less water will flow out.
Cuba

Seketul batu dimasukkan ke dalam tin Eureka yang penuh. 45 mℓ air mengalir ke dalam silinder penyukat. Berapakah isi padu batu itu?

溢水罐的答案 = jawapan tin Eureka 流进量筒的水就是被石头挤出来的水，所以石头的体积等于 45 mℓ，也就是 45 cm³（1 mℓ = 1 cm³）。45 cm² 用了面积单位；90 cm³ 是多算了一倍。 例子：一颗芒果放进溢水罐，流出 300 mℓ 的水，芒果的体积是 300 cm³。 注意：用溢水罐时不用减，量到的水就是答案。
the Eureka can answer = jawapan tin Eureka The water that flows into the cylinder is exactly the water pushed out by the stone, so the stone's volume is 45 mℓ, which is 45 cm³ (1 mℓ = 1 cm³). 45 cm² uses an area unit, and 90 cm³ doubles the amount. Example: a mango lowered into a Eureka can pushes out 300 mℓ of water, so the mango's volume is 300 cm³. Watch out: with a Eureka can there is no subtraction; the water collected is the answer.
Ingat semula

Rumusan Bab 6

Luas dan isi padu

Luas

cm² · m² · km² · kertas petak, kertas graf

Isi padu

mℓ · ℓ · m³ · cm³ · kubus, silinder penyukat, tin Eureka

Mengapa ukur?

hasil tepat · elak pembaziran
复习第六章 = ingat semula Bab 6；浪费 = pembaziran；存钱罐 = tabung syiling 第六章学了两件事：面积和体积。面积的单位是 cm²、m²、km²，用方格纸或坐标纸来量和估计；体积的单位是 mℓ、ℓ、m³、cm³，用小方块、量筒和溢水罐来量。量得准确可以避免浪费，例如用旧盒子做存钱罐前先量好大小，就不会剪错、浪费材料。 例子：爸爸铺地砖前先量地板面积，就能买刚好够用的地砖。 注意：面积单位右上角是 2，体积单位右上角是 3。
reviewing Chapter 6 = ingat semula Bab 6; waste = pembaziran; coin box = tabung syiling Chapter 6 covered two things: area and volume. Area uses cm², m² and km² and is measured or estimated with squared or graph paper. Volume uses mℓ, ℓ, m³ and cm³ and is measured with cubes, a measuring cylinder and a Eureka can. Accurate measuring prevents waste; for example, measuring an old box before turning it into a coin box means no wrong cuts and no wasted material. Example: Dad measures the floor area before tiling, so he buys just enough tiles. Watch out: area units carry a small 2, while volume units carry a small 3.
Mari jawab

Bagaimanakah 45 cm² ditulis dalam perkataan?

单位写成文字 = tulis unit dalam perkataan cm 是 sentimeter，右上角的小 2 读作 persegi，所以 45 cm² 写成 empat puluh lima sentimeter persegi。sentimeter padu 是 cm³（体积）；meter persegi 是 m²，单位大了一百倍。 例子：12 m³ 写成 dua belas meter padu。 注意：persegi 配 2（面积），padu 配 3（体积）。
writing units in words = tulis unit dalam perkataan cm is sentimeter and the small 2 at the top right is read persegi, so 45 cm² is written empat puluh lima sentimeter persegi. Sentimeter padu means cm³, which is volume, and meter persegi means m², a much bigger unit. Example: 12 m³ is written dua belas meter padu. Watch out: persegi goes with 2 (area) and padu goes with 3 (volume).
Mari jawab

Ayah Lim tidak mengukur luas lantai sebelum membeli jubin. Apakah mungkin berlaku?

不量面积的后果 = akibat tidak mengukur luas 不知道地板有多大，就不知道要买多少地砖：买少了不够铺，要再跑一趟；买多了用不完，浪费钱。地板不会因此变大，地砖也不会自己变小。 例子：妈妈缝窗帘前不量窗户，布可能太短或剩下一大块。 注意：这就是“量得准确可以避免浪费”的意思。
the result of not measuring = akibat tidak mengukur luas Without knowing how big the floor is, Ayah cannot know how many tiles to buy. Too few means the floor is not finished and another trip is needed; too many means leftover tiles and wasted money. The floor will not grow, and the tiles will not shrink. Example: if Mother sews curtains without measuring the window, the cloth may be too short or leave a big piece unused. Watch out: this is what accurate measuring to avoid waste means.
KBAT

Sebatang paku dimasukkan ke dalam bekas air yang penuh di dalam sebuah besen. Air yang melimpah ke besen disedut dengan picagari: bacaannya 3 mℓ. Berapakah isi padu paku?

用针筒量小钉子 = ukur paku dengan picagari 钉子很小，放进量筒水位几乎看不出变化。所以把装满水的容器放在盆里，放进钉子，溢出到盆里的水再用有细刻度的针筒吸起来量。溢出来 3 mℓ，钉子的体积就是 3 mℓ，也就是 3 cm³。不是 6 cm³，也不是 0。 例子：放进五颗同样的钉子，溢出 15 mℓ，每颗大约 3 mℓ。 注意：这是溢水罐方法的变化，道理一样：溢出的水 = 物体的体积。
measuring a small nail with a syringe = ukur paku dengan picagari A nail is so small that the level in a measuring cylinder hardly changes. So a full container of water is placed in a basin, the nail is dropped in, and the water that overflows into the basin is sucked up with a syringe, which has fine scale marks. 3 mℓ overflowed, so the nail's volume is 3 mℓ, which is 3 cm³, not 6 cm³ and not 0. Example: dropping in five identical nails makes 15 mℓ overflow, about 3 mℓ each. Watch out: this is a variation of the Eureka can idea: the overflowing water equals the object's volume.
Ringkasan

Syabas!

Akhir − awal = isi padu objek

Isi padu cecair dibaca pada bahagian bawah meniskus dengan mata separas. Isi padu pepejal tidak sekata ditentukan melalui kaedah sesaran air.

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