试题与答案

[物理-选修2-2] (1)常见的传动方式有______、______、____

题型:问答题

题目:

[物理-选修2-2]

(1)常见的传动方式有______、______、______轮传动等.齿轮传动的传动比是主动轮与______的转速之比,传动比等于______与______的齿数之比.

(2)液压千斤顶是利用密闭容器内的液体能够把液体所受到的压强向各个方向传递的原理制成的.图为一小型千斤顶的结构示意图.大活塞A的直径D1=20cm,小活塞B的直径D2=5cm,手柄的长度OC=50cm,小活塞与手柄的连接点到转轴O的距离DO=10cm.现用此千斤顶使质量m=4×103 kg的重物升高了h=10cm.g取10m/s2

求(ⅰ)者此千斤顶的效率为80%,在这一过程中人做的功为多少?

(ⅱ)若此千斤顶的效率为100%,当重物上升时,人对手柄的作用力.

答案:

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参考答案:D

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