Mr. Allen held out a glass of water with three ice cubes in it. “Why do things float?” he asked the class. No one said a word. The whole class was 1 . “Anyone?” Mr. Allen smiled at his students. “Let’s brainstorm some answers.” He swirled (旋动) the glass gently....
(二)Why do balloons float in the air?Balloons have air in them. 1 is a gas. A gas is a kind of matter(物 ).liquid solid It has mass(质量) and takes up space. You can't 2 air. But you can feel it gas when it moves. A gas has no shape. It takes the shape of the ...
Why do things float? A study of the place for alternative models in school science.Selley, Nicholas
skip to main content rhett allain science jul 9, 2011 8:47 am why do astronauts float around in space? this is a great question. it comes up quite often. if you ask the people around you, there are two common answers: astronauts float around in space because there is no gravity in ...
Why do things float in water? Objects are made up of very tiny molecules. Molecules can be packed in close together like in a rock or more spread out like in bubble wrap. The positioning of molecules affects the density of an object. Objects with tightly packed molecules are more dense th...
These focuses are not so different from the things in which they delight. 出自-2015年12月阅读原文 Criticism, at its best, is deeply personal, and gets to the heart of why we write the way we do. 出自-2015年12月阅读原文 Leo, why do you say English will become the world language?
We’ve talked about healthy bathroom habits and ways to resolve constipation, and today we will discuss the buoyancy of poop in particular. Whether your poops bob at the surface or dive to the bottom can be a sign of many things to do with your health and nutritional status. Here are ...
But way more satellites than people have been in space: more than 11,000 have launched in the past 60 years. Satellites can do a lot of things, even carry live cargo. A dog named Laika rode in the Sputnik 2 satellite in the late 1950s. The satellite that’s been in orbit the ...
In space your eyes get very dry and the added moisture is annoying. Sometimes things get even unusual. The astronaut Ron Parise told The Atlantic that when tears get big enough they “break free of the eye and float around”. No one can be quite sure why we cry. Why should water in ...
In the presentation Q&A, he added: “It has to be really fun and exciting, it can’t feel cramped or boring. The crew compartment is set up so that you can do zero-g games, you can float around, there will be movies, lecture halls, cabins, a restaurant—it’ll be really fun to...