I'm guessing you mean a medium? Waves can travel through any material, even a vacuum. but the general term for all of them would be a medium.
Answer: Scientists used relative dating and absolute dating.
Explanation:
Scientists used absolute dating to determine the actual number of years ago that events happened. They used relative dating to divide Earth's past into several time frames when similar organisms were on Earth.
Answer:
B. Quantum Mechanics
Explanation:
Quantum mechanics is the foundation of all quantum physics including quantum chemistry, quantum field theory, and quantum information science.
Answer:
14.8 kg
Explanation:
We are given that




We have to find the mass of the pulley.
According to question



Moment of inertia of pulley=

Where 



Hence, the mass of the pulley=14.8 kg