Sound is produced by vibrations. What is the speed of sound in air? A. 340 meters per second. B. 340 kilometers per hour. C. 3400 meters per second. D. 3400 kilometers per hour. 相关知识点: 试题来源: 解析 A。解析:声音在空气中的传播速度是 340 米每秒。选项 B、C、D 速度错误。
1. What's the speed of sound at 2500 meters above sea level?相关知识点: 试题来源: 解析 285.3米/秒 声音速度受温度和气压影响。在2500米海拔,气压约为海平面的0.75倍,温度约为-2摄氏度。根据公式c = 331.5 + 0.6T,在-2摄氏度时,声音速度约为330.3米/秒。由于声音速度与气压平方根成正比,因此在...
Articles are usually received within 1-2 days and books in 5-10 days. However, obtaining items that are rare, recently published or in high demand may take longer. To speed up the process, please make sure the information you submit through the ILL Request Form is accurate. Length of Loan...
•The last day to cancel registration and receive a full refund(退款) is June 15. Camp Structure The day is divided into two thematic sessions per age group. Campers have a three- hour morning class engaging with a morning theme (9am to 12 noon) and a one-hour lunch break, followed ...
At slow speeds, that change in density is imperceptible. At the speed of light, it's a different story. Related: What would happen if the speed of light were much lower? "What would happen is you have pretty humid air [during a lightning storm], the sound wave comes through and ...
百度试题 结果1 题目4. What is the fastest speed in nature? A.The speed of sound. B.The speed of Usain Bolt. C.The speed of light. D.The speed of a jet plane.相关知识点: 试题来源: 解析 C 反馈 收藏
For example, scientists used what they saw in nature to improve our way of travelling. In days of high-speed train research and development,scientists were once faced with 3.noise problem. The trains pushed air through tunnels at high speeds. 4.when a train came out of a tunnel, it ...
Discover how different aspects of the workplace will be changed in response to the 2020’s dramatic decade and what the new work life will look like.
The most difficult step in programming values will be deciding exactly what we believe is moral, and how to create a set of ethical rules. 出自-2016年6月阅读原文 Such moves may eliminate the fears of those living in the exporting countries, but they are creating panic in importing countries...
But how long before the current generation of airliners reaches its limits? From electric propulsion to hypersonics, from NASA to private entrepreneurs, the quest for new, truly groundbreaking, aircraft concepts is on. And it has the potential to forever change our idea of air travel. High...