想获取更多增值,教师端:初中物理——天星教师交流群5612078091学生端:天星初中生学习交流群434612457
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大同市2019—2020学年度第一学期期末教学质量监测八年级物理答案一、选择题:(每题3分,共30分)题号12345678910选项CDCACBBCAC二、实验探究(本大题共6个小题,11小题7分,12小题5分,13小题5分,14小题7分,15小题8分,16小题4分,共36分)11.(1)BDAC(2)96(3)已经沸腾(4)①如图所示②先快后慢不变(5)水沸腾的过程中需要不断吸热12.(1)显示光的传播径迹(2)不能同一(3)在光的反射现象中,光路是可逆的(4)改变入射角,多次测量反射角与入射角,比较其大小关系13.(1)2(2)较暗(3)大小(4)左玻璃板与水平桌面不垂直14.(1)点燃(2)①倒立缩小②倒立放大3(3)上(4)C(5)凸透镜没有正对着太阳光15.(1)水平零刻线左(2)0.0423(3)③40④1.05×10(4)偏大小烧杯中的水倒入量筒时有挂杯现象,测得的鸡蛋体积偏小,密度偏大。
16.(1)实验物品:一杯水、两块玻璃片、滴管。(1分)(2)实验步骤:a、用滴管在两块玻璃板上滴上等量的水,并使它们的表面积不同,将它们放在同样的环境当中;b、比较两块玻璃板上水蒸发的快慢。(2分)(3)实验现象:表面积大蒸发的快。(1分)三、综合应用(本大题共10个小题,17小题2分,18小题4分,19小题3分,20小题4分,21小题3分,22小题4分,23、24小题各2分,25、26小题各5分,共34分)17.满液体的热胀冷缩18.(1)变小(2)倒立(3)能(4)不变19.降低熔化可以20.(1)凸透中间厚、边缘薄、能透光虚像(2)请勿随意丢弃垃圾(讲文明语,做文明事,当文明人,文明礼仪从我做起)(开放性试题,答案合理即可)21.(1)小(2)C(3)B22.我国北方冬天气温低,水管内的水会凝固结冰(1分),由于水的密度大于冰的密度(1分),根据V=m/ρ(或ρ=m/v)(1分),一定质量的水结冰后体积变大,就容易将水管涨裂。(1分)23.24.25.(1)OA段的路程sOA=1800m,时间tOA=25min=1500s,速度vOA=sOA/tOA=1800m/1500s=1.2m/s·························································(1分)AB段的路程sAB=3600m-1800m=1800m,时间tAB=30min-25min=5min=300s,速度vAB=sAB/tAB=1800m/300s=6m/s····························································(1分)vOA﹤vAB,所以小明骑车的是图甲中的AB段.····················································(1分)(2)由交通指示牌可知:v=80km/h,S=40km······················································(1分)t=S/v=40km/80km/h=0.5h··································································(1分)33326.已知m蜡=1.8gρ蜡=0.9×10kg/m=0.9g/cmm锡=14.56gm蜡1.8g3V蜡==3=2cm··································································(2分)蜡0.9g/cm3V锡=V蜡=2cm·······························································································(1分)m14.56g3锡==7.28g/cm·································································(2分)锡3V2cm锡