The primitive Earth was a mass of molten rock. What was the main factor that made it molten? A. Radioactive decay B. Gravitational compression C. Impact heating D. All of the above 相关知识点: 试题来源: 解析 D。解析:原始地球是一团熔融的岩石。A选项放射性衰变会释放出热量,这有助于地球...
百度试题 题目中国大学MOOC: 地球质量是多少?What is the mass of the Earth?相关知识点: 试题来源: 解析反馈 收藏
Question: What is the weight (in Newtons) of an object with a mass of 25 kg on the surface of the Earth?. Weight of An Object: Weight is defined as the gravitational pull on a mass. If a mass {eq}m {/eq} is in gravitational field {eq}g {/eq}...
The radius of the earth is r. A satellite of a mass 100 kg is at a point 3r above the earth's surface. What is the satellite's weight? A 390-kg satellite is in orbit around the Earth 21,000 km above the Earth's su...
However, Starship's hull is stainless steel, which makes it more durable than other rockets but also extremely heavy. At 5,000 tons, it has twice the dry mass of the SLS. NASA's rocket can make it all the way to the moon in one launch, but Starship will have to refuel in orbit....
月球的质量为地球的八十分之一。The mass of the moon is ___. A. 1/80 what the earth is B. 1/80 tha
MALE PROFESSOR: There is evidence that the solar wind was more intense in the past,but we don't know for sure how much mass our Sun's lost over the last four billion years.Astronomers tried to estimate what solar mass could produce the required luminosity to explain liquid water on these...
The Antarctic Icecap is the largest supply of fresh water, representing nearly 2% of the world' s total of fresh and salt water. As can be seen from the table above, the amount of water in our atmosphere is over 10 times as much as the water in all the rivers taken together. The ...
The centripetal force keeps an object moving in a circle and is always pointed toward the center of that circle. For instance, the gravitational force of the sun is a centripetal force that keeps Earth orbiting it. Meanwhile, the centrifugal force is what's known as a fictitious force: It'...
The discovery of a Permian-Triassic boundary section in northeastern Utah provided an opportunity to study the chemistry and geology associated with this event that led to one of the greatest mass extinctions on the planet. From 83% to 97% of the species living on the planet went extinct ...