A baseball is hit straight up with an initial velocity of 30m/s what is the initial speed

With i really need the correct answer!

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 most useful equation for electric power?