Sound is produced by vibrations. When an object vibrates, it makes sound. How is sound produced? A. By colors. B. By vibrations. C. By shapes. 相关知识点: 试题来源: 解析 B。解析:声音是由振动产生的,B 选项正确。A 选项颜色和声音产生无关,C 选项形状也不是声音产生的原因。
1hat is sound?Sound isWcreated when an objectvibrates(振动).Thevibrations travel in waves.Sound waves reach our ears.The ears send a message to the brain.That's how wehear different sounds!A sound can be loud or quiet.Itcan have a high pitch(音高)or a low pitch.Here are9a few diffe...
Mark ZZ 无所不好 Natural frequency is the frequency at which an object vibrates when it is disturbed. It is determined by the object's mass and stiffness. Objects with a lower mass and a higher stiffness will have a higher natural frequency. Objects with a higher mass and a lower ...
A wobbly washer can make rattling sounds as it vibrates. Leveling will prevent this • Make sure nothing is in contact with the washer. As an example, a common cause for a rattling noise is the power cord of the washer leaning against the washer as it vibrates • Check the tub fo...
(Image credit: Tom's Hardware) Some materials like ABS are prone to warping due to its thermal properties, specifically, the rate at which it cools and contracts. The temperature differences cause the corners of the print to lift, leading to a failed or distorted object, and sometimes the ...
a)、Normal mice usually live for two years. )、正常老鼠通常居住二年。[translate] aIssue an error, with a description of what object is missing, and where it was referenced, and unload the paradigm. 发布一个错误,以什么对象的描述是缺掉的,并且它参考了的地方,并且卸载范例。[translate] ...
B.The piano has strings and a keyboard. C.We strike gongs and xylophones. D.We can group musical instruments into families by how they produce vibrations. E.Sometimes we strike an object that has a skin or other membrane (膜) stretched tight across it. ...
thecane.Itworkedout! HowtheCaneWorksThecanesendsoutsoundwaves.Whenanechoissentback,thetopofthecanevibrates(震动).Thishelpstheperson 9 thecaneknowhowfarawayanobjectis.Heorshewillalsoknowhowbigtheobjectis. The 10 ofthecaneshowsthatnatureisreallywheregreatideascomefrom.()1.A.useful B.interestingC.imp...
→ It might be cause either by an unbalanced load of laundry, or some foreign substance. The washing tub rotates at a quick speed during a spin cycle. If a load of laundry is small(i.e. one or two pairs of jeans) or big(i.e. several blankets), the tub may become unbalanced...
the literary form of autobiography(北二外 2008 研) Key: the literary form of autobiography:An autobiography is a person‘s account of his or her life. It is generally written in the first person, with the author speaking as ―I‖. Autobiography presents life events as the writer views them...