为什么自行车换档爬坡会更轻松？
Why does shifting gears make a bike easier to climb hills?
自行车的齿轮大小不同，换到小牙盘配大飞轮时，每踩一圈轮子转得少但更用力。这样把力气放大，上坡就不用使那么大的劲。
A bike's gears differ in size; shifting to a small front gear with a large rear one means each pedal turn spins the wheel less but with more force. The force is magnified, so hills feel easier.
难度 入门 · 适合 小学高段(9-12)
CC BY 4.0 · 已核验 · Verified 2026-08-23 · 2 条独立证据
来源 · Source
David Macaulay,《The Way Things Work》,Houghton Mifflin,1988;中译《万物运转的秘密》
D. Macaulay, The Way Things Work, Houghton Mifflin, 1988; Chinese ed.
独立核验依据 · Independent verification: 核验依据 2 OPENLIBRARY 标识 /works/OL15130328W：The Way Things Work（按标
#自行车 #齿轮 #省力
为什么跷跷板能轻松抬起小伙伴？
Why can a seesaw lift a friend so easily?
跷跷板是一根杠杆，中间有个支点。坐得离支点远一点，轻轻一压就能把另一边的人抬起来。
A seesaw is a lever with a pivot in the middle. Sit farther from the pivot and a small push lifts the person on the other side.
难度 入门 · 适合 幼儿(3-6)
CC BY 4.0 · 已核验 · Verified 2026-08-23 · 2 条独立证据
来源 · Source
David Macaulay,《The Way Things Work》,Houghton Mifflin,1988;中译《万物运转的秘密》
D. Macaulay, The Way Things Work, Houghton Mifflin, 1988; Chinese ed.
独立核验依据 · Independent verification: 核验依据 2 OPENLIBRARY 标识 /works/OL15130328W：The Way Things Work（按标
#杠杆 #跷跷板 #支点
为什么斧头能劈开木头？
Why can an axe split wood?
斧头刃是尖尖的楔子，砸下去时把木头往两边推开。力集中到尖头，木头就裂开了。
An axe blade is a sharp wedge that pushes wood apart as it is swung down. The force gathers at the tip and the wood splits.
难度 入门 · 适合 小学低段(6-8)
CC BY 4.0 · 已核验 · Verified 2026-08-23 · 2 条独立证据
来源 · Source
David Macaulay,《The Way Things Work》,Houghton Mifflin,1988;中译《万物运转的秘密》
D. Macaulay, The Way Things Work, Houghton Mifflin, 1988; Chinese ed.
独立核验依据 · Independent verification: 核验依据 2 OPENLIBRARY 标识 /works/OL15130328W：The Way Things Work（按标
#斧头 #楔子 #木头
为什么给箱子装轮子就更省力？
Why is a box easier to move when it has wheels?
轮子把滑动变成滚动，滚动时地面只轻轻蹭着轮子。这样不用花大力气就能把东西推走。
Wheels turn sliding into rolling, and the ground only lightly touches them as they turn. That lets you push heavy things with little effort.
难度 入门 · 适合 幼儿(3-6)
CC BY 4.0 · 已核验 · Verified 2026-08-23 · 2 条独立证据
来源 · Source
David Macaulay,《The Way Things Work》,Houghton Mifflin,1988;中译《万物运转的秘密》
D. Macaulay, The Way Things Work, Houghton Mifflin, 1988; Chinese ed.
独立核验依据 · Independent verification: 核验依据 2 OPENLIBRARY 标识 /works/OL15130328W：The Way Things Work（按标
#轮子 #滚动 #省力
为什么螺丝能紧紧把东西固定住？
Why can a screw hold things tightly together?
螺丝身上有斜斜的纹路，转进去时像走斜坡一样往里钻。纹路咬住材料，东西就被牢牢锁住。
A screw has a slanted ridge that drills inward like a ramp as you turn it. The ridge bites into the material and locks things firmly.
难度 入门 · 适合 小学低段(6-8)
CC BY 4.0 · 已核验 · Verified 2026-08-23 · 2 条独立证据
来源 · Source
David Macaulay,《The Way Things Work》,Houghton Mifflin,1988;中译《万物运转的秘密》
D. Macaulay, The Way Things Work, Houghton Mifflin, 1988; Chinese ed.
独立核验依据 · Independent verification: 核验依据 2 OPENLIBRARY 标识 /works/OL15130328W：The Way Things Work（按标
#螺丝 #纹路 #固定
为什么门把手转一下就能开门？
Why does turning a doorknob open the door?
门把手其实是个小轮轴，转动时带动里面的机关。轻轻一转就把锁舌拉开，门就开了。
A doorknob is really a small wheel-and-axle; turning it works the latch inside. A gentle turn pulls the bolt back and the door opens.
难度 入门 · 适合 小学低段(6-8)
CC BY 4.0 · 已核验 · Verified 2026-08-23 · 2 条独立证据
来源 · Source
David Macaulay,《The Way Things Work》,Houghton Mifflin,1988;中译《万物运转的秘密》
D. Macaulay, The Way Things Work, Houghton Mifflin, 1988; Chinese ed.
独立核验依据 · Independent verification: 核验依据 2 OPENLIBRARY 标识 /works/OL15130328W：The Way Things Work（按标
#门把手 #轮轴 #机关
为什么说螺丝其实是卷起来的斜坡？
Why is a screw really an inclined plane wrapped around?
螺丝上的纹路如果摊平，就是一条绕圈上升的斜坡。转螺丝时就像推着东西沿斜坡往上走，所以能用小力气拧进很硬的材料。
If you unroll a screw's ridge, it becomes a ramp that coils upward. Turning the screw is like pushing along that ramp, so a small twist drives it into hard material.
难度 入门 · 适合 小学高段(9-12)
CC BY 4.0 · 已核验 · Verified 2026-08-23 · 2 条独立证据
来源 · Source
David Macaulay,《The Way Things Work》,Houghton Mifflin,1988;中译《万物运转的秘密》
D. Macaulay, The Way Things Work, Houghton Mifflin, 1988; Chinese ed.
独立核验依据 · Independent verification: 核验依据 2 OPENLIBRARY 标识 /works/OL15130328W：The Way Things Work（按标
#螺丝 #斜坡 #纹路
为什么把好几个滑轮连起来能吊起更重的东西？
Why can linking several pulleys lift something even heavier?
把多个滑轮串成滑轮组，绳子要绕更长的路，重量就被分到更多段绳子上。每段只扛一小部分，人拉起来就轻松得多。
Stringing several pulleys into a block-and-tackle makes the rope travel a longer path, spreading the load across more rope sections. Each section holds only a small part, so pulling feels much easier.
难度 入门 · 适合 小学高段(9-12)
CC BY 4.0 · 已核验 · Verified 2026-08-23 · 2 条独立证据
来源 · Source
David Macaulay,《The Way Things Work》,Houghton Mifflin,1988;中译《万物运转的秘密》
D. Macaulay, The Way Things Work, Houghton Mifflin, 1988; Chinese ed.
独立核验依据 · Independent verification: 核验依据 2 OPENLIBRARY 标识 /works/OL15130328W：The Way Things Work（按标
#滑轮组 #绳子 #省力
为什么用滑轮能拉起很重的东西？
Why can a pulley help lift something heavy?
滑轮是一个会转的小轮子，绳子绕在上面。你往下拉绳子，轮子就把力换了个方向，把另一头的东西提起来——站着往下拉比弯腰往上抬更方便。
A pulley is a small turning wheel with a rope over it. When you pull the rope down, the wheel changes the force's direction and lifts the object on the other end—pulling down while standing is handier than bending to lift up.
难度 入门 · 适合 幼儿(3-6)
CC BY 4.0 · 已核验 · Verified 2026-08-23 · 2 条独立证据
来源 · Source
David Macaulay,《The Way Things Work》,Houghton Mifflin,1988;中译《万物运转的秘密》
D. Macaulay, The Way Things Work, Houghton Mifflin, 1988; Chinese ed.
独立核验依据 · Independent verification: 核验依据 2 OPENLIBRARY 标识 /works/OL15130328W：The Way Things Work（按标
#滑轮 #绳子 #省力
为什么撬棍能撬动很重的大石头？
Why can a crowbar pry up a heavy rock?
撬棍是一根长杠杆，把支点放在靠近石头的地方。手在另一头轻轻一压，远端的力就被放得很大，石头就松动了。
A crowbar is a long lever with its pivot placed near the rock. A small push at the far end becomes a much larger force at the rock, loosening it.
难度 入门 · 适合 小学高段(9-12)
CC BY 4.0 · 已核验 · Verified 2026-08-23 · 2 条独立证据
来源 · Source
David Macaulay,《The Way Things Work》,Houghton Mifflin,1988;中译《万物运转的秘密》
D. Macaulay, The Way Things Work, Houghton Mifflin, 1988; Chinese ed.
独立核验依据 · Independent verification: 核验依据 2 OPENLIBRARY 标识 /works/OL15130328W：The Way Things Work（按标
#撬棍 #杠杆 #支点
为什么走斜坡比直接爬高台轻松？
Why is a ramp easier than climbing straight up?
斜坡把又高又陡的路拉长了。一步步慢慢上，每次只用一点点力，就不那么累。
A ramp stretches a steep climb into a longer, gentler path. You use a little force many times, so it feels much easier.
难度 入门 · 适合 幼儿(3-6)
CC BY 4.0 · 已核验 · Verified 2026-08-23 · 2 条独立证据
来源 · Source
David Macaulay,《The Way Things Work》,Houghton Mifflin,1988;中译《万物运转的秘密》
D. Macaulay, The Way Things Work, Houghton Mifflin, 1988; Chinese ed.
独立核验依据 · Independent verification: 核验依据 2 OPENLIBRARY 标识 /works/OL15130328W：The Way Things Work（按标
#斜坡 #省力 #高度