Science

小四自然科學 互動複習網頁

💡 互動指南：
1. 網頁中所有底下一條虛線的英文句子/單字，用滑鼠點擊一下，瀏覽器就會用標準英文發音讀給聽喔！
2. 思考完答案後，點擊「顯示正確答案與解析」即可進行校對。

✨ Part A: Energy & Light (位能、動能與光學)

Q3. Which rubber band is storing potential energy?

A) A

B) B

C) both A and B

D) neither

正確答案：B) B

觀念解析：位能（Potential energy）是儲存在物體中的能量。緊緊扭轉的橡皮筋（Tightly wound）產生了形變，因此儲存了能量。

Q4. What kind of energy is stored in the rubber band?

A) Chemical Potential

B) Gravitational Potential

C) Elastic Potential

D) Kinetic

正確答案：C) Elastic Potential

觀念解析：橡皮筋因為被拉長或扭轉而產生的位能，叫做彈性位能（Elastic Potential Energy）。

Q5. A shadow will be larger if it is ________ the light source.

A) closer to

B) farther from

C) over

D) under

正確答案：A) closer to

觀念解析：不透明物體**越靠近光源**時，擋住的光線範圍越大，投影出來的影子就會越大。

Q7. If you blow across the top of the bottles below, they can make a whistling sound. Number the bottles 1-7, with 1 being the lowest pitch and 7 the highest.

正確答案（由左至右，水最滿到最空）：7, 6, 5, 4, 3, 2, 1

觀念解析：對瓶口**吹氣**時，振動發聲的是「空氣柱」。水裝得越滿（最左邊），空氣柱越短，振動越快，音調就越**高 (7)**；反之，空瓶（最右邊）空氣柱最長，振動最慢，音調最**低 (1)**。

Part 6. Put the sentences in order, 1,2,3, to describe how we see the moon. (排序題)

(   ) The Moon reflects light from the Sun into our eyes.

(   ) The Sun produces light.

(   ) Light from the Sun shines directly onto the Moon.

正確順序（由上至下）：3, 1, 2

觀念解析：光傳播的順序為：太陽自身發光 (1) → 太陽光照到月球上 (2) → 月球將光線反射到我們的眼睛 (3)。

Part 7 - Q1. Why does the bottom car have more kinetic energy?

A) It is moving slower than the top car.

B) It is moving the same speed as the top car.

C) It is moving faster than the top car.

D) It does not have more kinetic energy.

正確答案：C) It is moving faster than the top car.

觀念解析：動能（Kinetic energy）和速度有關。車子大小相同時，速度越快，動能就越多。

Part 7 - Q2. Which object(s) have the most Gravitational Potential Energy?

A) A, because it is closer to the ground.

B) C, because it is higher, and larger than B.

C) B and C, because they are both higher than A.

D) None of the objects has Gravitational Potential Energy.

正確答案：B) C, because it is higher, and larger than B.

觀念解析：重力位能與物體的「高度」和「重量（質量）」有關。位置越高、重量越重，重力位能越大。C 和 B 都最高，但 C 比 B 大（重），所以 C 的重力位能最大。

✨ Part B: Light Materials & Sound Properties (透光材料與聲音性質)

Q5. What is an example of an **opaque** material? → 答案：thick book (不透光物體)

Q6. What type of material is a **clear glass window**? → 答案：transparent (透明材料)

📊 Materials Chart (透光度對照表)

type of material	amount of light	example
transparent (透明)	almost all (幾乎全部)	glass window
translucent (半透明)	some (部分)	frosted glass
opaque (不透明)	none (完全沒有)	thick book

1. What material allows **almost all** light to pass through? → Answer: transparent

2. How much light do **opaque** objects allow to pass through? → Answer: none

3. What is an example of a **translucent** material? → Answer: frosted glass

4. What type of material only lets **some light** pass through? → Answer: translucent

✍️ Part C: True or False (是非題複習)