một vật dao động điều hòa có phương trình x=Acos(ωt+π). Gọi v và alaadn lượt là vận tớc và gia tốc của vật. Hệ thức đúng là

Waves are used in many practical applications to support work, entertainment, and health. one example is the use of ultrasound imaging to safely track the development of a growing fetus. what is a specific example of a practical application of waves in medicine, entertainment, safety, or other fields? provide a brief explanation of how the properties of waves are useful to that application.

The softest and hardest minerals are: softest hardest

Which levels of government establish and implement educational requirements for minors