小胖看见闪电后,过了5.2秒才听到雷声.已知雷声在空中传播的速度是0.33千米/ 发布时间:2017-05-24 17:14 │ 来源:www.tikuol.com 题型:解答题 问题: 小胖看见闪电后,过了5.2秒才听到雷声.已知雷声在空中传播的速度是0.33千米/秒.闪电的地方离小胖有多远?
题型:解答题 质量为5 kg的小球以5 m/s的速度竖直落到地板上,随后以3 m/s的速度反向弹回去,若取竖直向下的方向为正方向,则小球动量的变化为[ ]A.10 kgm/s B.-10 kgm/sC.40 kgm/s D.-40 kgm/s 查看答案
题型:解答题 用方框内的单词完成下面的句子(有多余选项)。 always, every day, often, sometimes, never, hardly ever 1. He_____ gets up at six o'clock, seven days a week.2. How_____ do you go to the movies? 3. It _____ _____ rains here. It's usually sunny and warm. 4. Some of my friends exercise every day and hardly ever eat junk food, but most of them eat junk food _____ .5. I can't swim. So I _____ go to the beach to swim. Sometimes I go there with my friends to run. 查看答案