《压强和浮力》单元测试题二（参考答案）

压强和浮力单元测试题二（参考答案）DIV.MyFav_1324346330588 P.MsoNormalTEXT-JUSTIFY: inter-ideograph; FONT-SIZE: 10.5pt; FONT-FAMILY: Times New Roman; TEXT-ALIGN: justifyDIV.MyFav_1324346330588 LI.MsoNormalTEXT-JUSTIFY: inter-ideograph; FONT-SIZE: 10.5pt; FONT-FAMILY: Times New Roman; TEXT-ALIGN: justifyDIV.MyFav_1324346330588 DIV.MsoNormalTEXT-JUSTIFY: inter-ideograph; FONT-SIZE: 10.5pt; FONT-FAMILY: Times New Roman; TEXT-ALIGN: justifyDIV.MyFav_1324346330588 P.MsoHeaderBORDER-RIGHT: medium none; PADDING-RIGHT: 0cm; BORDER-TOP: medium none; PADDING-LEFT: 0cm; FONT-SIZE: 9pt; PADDING-BOTTOM: 0cm; BORDER-LEFT: medium none; LAYOUT-GRID-MODE: char; PADDING-TOP: 0cm; BORDER-BOTTOM: medium none; FONT-FAMILY: Times New Roman; TEXT-ALIGN: centerDIV.MyFav_1324346330588 LI.MsoHeaderBORDER-RIGHT: medium none; PADDING-RIGHT: 0cm; BORDER-TOP: medium none; PADDING-LEFT: 0cm; FONT-SIZE: 9pt; PADDING-BOTTOM: 0cm; BORDER-LEFT: medium none; LAYOUT-GRID-MODE: char; PADDING-TOP: 0cm; BORDER-BOTTOM: medium none; FONT-FAMILY: Times New Roman; TEXT-ALIGN: centerDIV.MyFav_1324346330588 DIV.MsoHeaderBORDER-RIGHT: medium none; PADDING-RIGHT: 0cm; BORDER-TOP: medium none; PADDING-LEFT: 0cm; FONT-SIZE: 9pt; PADDING-BOTTOM: 0cm; BORDER-LEFT: medium none; LAYOUT-GRID-MODE: char; PADDING-TOP: 0cm; BORDER-BOTTOM: medium none; FONT-FAMILY: Times New Roman; TEXT-ALIGN: centerDIV.MyFav_1324346330588 P.MsoFooterFONT-SIZE: 9pt; LAYOUT-GRID-MODE: char; FONT-FAMILY: Times New RomanDIV.MyFav_1324346330588 LI.MsoFooterFONT-SIZE: 9pt; LAYOUT-GRID-MODE: char; FONT-FAMILY: Times New RomanDIV.MyFav_1324346330588 DIV.MsoFooterFONT-SIZE: 9pt; LAYOUT-GRID-MODE: char; FONT-FAMILY: Times New RomanDIV.MyFav_1324346330588 PFONT-SIZE: 12pt; MARGIN-LEFT: 0cm; MARGIN-RIGHT: 0cm; FONT-FAMILY: 宋体DIV.MyFav_1324346330588 PREFONT-SIZE: 12pt; FONT-FAMILY: 宋体DIV.MyFav_1324346330588 DIV.Section1page: Section1DIV.MyFav_1324346330588 OLMARGIN-BOTTOM: 0cmDIV.MyFav_1324346330588 ULMARGIN-BOTTOM: 0cm一、选择题1B 2C 3B 4B 5C 6D 7A 8B 9B 10C 11D 12A 13D 14A 15B 16C 17B 18A 19D 20D二、填空题21减小压强、增大压强；22变大、不变；23吸气、增大；24不变、浮起；25增大、减小；26大于、等于；27用一个硬纸片垫在塑料袋提手处、减小；28改变力的方向、3N；29流速大、小；30大气压强、水的浮力三、实验探究题31（1）密度、深度；（2）深度、盐水中；（3）A32（1）弹簧测力计，烧杯，水，体积相等的铜块和铝块，细线；（2）实验步骤：用弹簧测力计在空气中分别测出体积相等的铜块和铝块的重力分别为G铜和G铝。用弹簧测力计分别把铜块和铝块悬挂着完全浸入水中，测出二者的示数为G铜和G铝。比较二者所受到的浮力的大小（G铜- G铜）和（G铝- G铝），如果二者相等则说明浮力的大小与重力无关。33（1）排掉注射器中的空气；（2）V/L；（3）注射器的全部长度L/m；大气压强P/Pa；（4）FL/V；（5）注射器气密性不好，漏气。四、应用与实践34从题意中可知V排=510-4m20.1m=510-5m3F浮=水gV排=1.0103kg/m310N/kg510-5m3=0.5N，G= F浮=0.5N玻璃管漂浮，F浮=G=0.5N。F浮=盐水gV排=盐水10N/kg4.510-5m3=0.5N盐水=1.11103kg/m33