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一、填空题1.5千克力=____牛顿;740毫米水银柱=____帕斯卡;54千米/小时=____米/秒;5马力=____千瓦=____瓦特。2.斜面长6米,高1.5米,不计摩擦力,沿斜面用____牛顿的拉力可将784牛顿的重物拉上去,但因有摩擦力存在,实际上需用245牛顿的拉力,则此斜面的机械效率为____。3.如图1用滑轮组提起重物,若不计滑轮重量与摩擦,在A端所用的拉力F是物体重量的____倍。如把重物提高2米,绳的自由端要拉过的距离为____米。4.如图2所示的管内装有水银,h为5厘米,在下列空格内填入各管内封闭端空气柱的压强(大气压强为760毫米汞柱)。
First, fill in the blank 1.5 kg force = ____ Newton; 740 mm mercury = ____ Pascal; 54 km / h = ____ m / s; 5 horsepower = ____ kilowatts = ____ watts. 2. Bevel length of 6 meters, 1.5 meters high, excluding friction along the slope with ____ Newton’s pull can be 784 Newton’s weight pulled up, but because there is friction, in fact, need to use 245 Newtons pull, The mechanical efficiency of this bevel is ____. 3. As shown in Figure 1 using the pulley group to lift the weight, excluding the pulley weight and friction, the tension on the A side of the F is the object weight ____ times. If the weight increased by 2 meters, the free end of the rope to pull the distance ____ meters. 4. The tube shown in Figure 2 is filled with mercury and h is 5 cm. Fill the closed-end air column pressure (760 mmHg) in each tube with the following space.