Astronomy | Astrophysics Answers

how to produce a blast wave without explosion ?
and can shock waves/ blast waves be trapped into a certain path by ultrasonic waves ?

an object weighing 4200lbs hits a stationaty object weighing 3200lbs, and the 3200lb object is moved 113ft, how fast was the 4200lb moving at impact?

kinetic energy required to project a body of mass m from earths surface to infinity is mgR. Explain?

Effect of gravitional force in the solar system

Is it possible to build a sand castle on the moon? Our moon? I am the media person for the World Championship of Sand Sculpture. Management of the event asked for fun facts relating to sand and one that I have sent is the thought of building a sand castle on the moon. Footprints left there indicate to me that the moon dust or sand is very good in holding detail and with 1/6th the gravity, I would imagine some very incredible possibilities with sand sculpture there. However, sand needs water to stick together. How would the sand grains accept water? How would water react with no atmospheric pressure and no atmoshere? I will most likely be interviewed by media regarding this "fun fact" question and I want to give an accurate answer. Is there anyone out there that can help me?
Email: jgowdy@aol.com

If an atom is found to be mostly empty space, is it possible our universe is just an atom in a much larger matter or creature?

Q1) A planet equivalent to Earth in size and mass orbits a star equivalent to the Sun in energy output, as a distance equivalent to that of Mercury. What is its effective temperature?
How would this change if the planet were 5 times the diameter of Earth?
Assume Stefan’s constant σ=5.67x10–8 Js–1m–2K–4

why earth is elliptical in shape and its advantages