It depends on your definition of “ancient.” Radiometric dating using Carbon-14 can reliably date back to about 50,000 years, uranium-lead or lead-lead dating can date back multiple millions, potassium-argon dating can reach 1.5 billion, and rubidium-strontium can reach 50 billion (nearly 4x the age of the universe). It depends on the context in which this question is being asked.
Answer:
The free end of the blade has a tangential velocity of about 88.19 m/s
Explanation:
The angular velocity of the blades is 
since the blades are 80 m long, then the tangential velocity of the free end of the blade is:

Answer:
The two methods will yield different results as one is subject to experimental errors that us the Archimedes method of measurement, the the density measurement method will be more accurate
Explanation:
This is because the density method using the calculated volume will huve room for less errors that's occur in practical method i.e Archimedes method due to human error
See the attached picture for answers
Answer:
an increase in gasses that absorb heat
Explanation:
Greenhouse effect refers to the gradual increase in the earth's temperature due to an increase in the concentration of certain gases in the atmosphere. These gases are called greenhouse gases and they include; water vapour, nitrogen 1 oxide, carbon IV oxide etc. Green house effect is said to occur when heat radiating outwards from the earth surface towards space is trapped close to the earth's surface due to the presence of greenhouse gases in the atmosphere.
Greenhouse effect leads to increase in the temperature of the earth, melting of polar ice caps and possibly flooding due to a rise in sea levels.
Greenhouse gases act as glass in a greenhouse. They allow heat to pass through onto the earth surface but trap the heat and prevent it from being radiated outwards back to space. Thereby increasing the surface temperature of the earth.