Forces always act alone. true or false

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.

What is the weight of a feather (mass = 0.0001 kg) that floats through earth's and the moon's atmospheres?

Ways that industry and agriculture use physical properties to separate substances