Related to pulleys:Simple Machines pul·ley (po͝ol′ē) n.pl.pul·leys 1.A simple machine consisting essentially of a wheel with a grooved rim in which a pulled rope or chain can run to change the direction of the pull and thereby lift a load. ...
A pulley is a simple machine made up of a wheel with two raised edges. A rope or a string runs along these raised edges without coming off. This is also known as the block and tackle pulley system which utilizes themechanical advantageof lifting a weight with only half the force to lift...
A differential pulley consists of two pulleys of different radii connected and rotating as one on a common axle. The pulleys have their circumferences grooved and spiked so that a chain will run in them without slipping. Over the pulleys an endless chain is run, forming two hanging loops. ...
n. 滑轮(组),滑车( pulley的名词复数 );皮带轮; 英英释义 pulley n.a simple machine consisting of a wheel with a groove in which a rope can run to change the direction or point of application of a force applied to the rope 同义词:pulley-blockblock ...
a measurement of how much a simple machine multiples a force. The bigger the mechanical advantage, the less force you need, but the greater the distance you have to use that force. The weight rises 1m, but now we have to pull the loose end of the rope twice as far (2m). How come...
A movable pulley is one in which drum moves as you are moving the load. There is no change in the direction of force that you need to apply, but the load will "feel" lighter than it is. If you were hauling a heavy hay bale up into the loft of a barn, for example, amovable pu...
Make science come alive as kids learn about levers and pulleys with these fun simple machine activities and experiments for kid of all ages!
The earliest evidence of pulleys dates back toAncient Egypt in the Twelfth Dynasty (1991-1802 BCE)and Mesopotamia in the early 2nd millennium BCE. In Roman Egypt, Hero of Alexandria (c. 10-70 CE) identified the pulley as one of six simple machines used to lift weights. ...
the evening. A simple machine called a pulley helps a person raise and lower the flag. A pulley is a wheel with a groove in it, and a rope in the groove. The wheel can be any size, and the length of the rope can vary as well. The wheel can also be called a drum or a ...
作者:Gardner, Robert 页数:48 ISBN:9781464401428 豆瓣评分 目前无人评价 评价: 写笔记 写书评 加入购书单 分享到 推荐 Simple Machine Experiments Using Seesaws, Wheels, Pulleys, and More的创作者· ··· Robert Gardner作者 我要写书评 Simple Machine Experiments Using Seesaws, Wheels, Pulleys, and Mor...