Answer:
At which point does the planet have the least gravitational force acting on it?
Explanation:
In an elliptical orbit, when a planet is at its furthest point from the Sun, it is under the least amount of gravity, meaning that the force of gravity is strongest when it is closest.
10 trillion km is the corrct asnwer
500m has 1 significant digit.
Because rockets do accelerate in space and have been able to do so for a long time.
Answer: Option D
<u>Explanation:</u>
A rocket is made to reach the sky and its required destination by the burning of fuels in the rocket. So there is no need of any other external forces to propel them in space. As per Newton's third law, the action and reaction forces will help the rockets to escape the orbit of earth.
And then the remaining energy required by the rocket to travel in space will be obtained from the burning of fuels in the compartments. This burning of fuels in respective compartments will propel the rockets in space. So it is a complete myth that space travel was impossible before because of inability to provide propulsion in space.
3. Nuclear power station or plants obtain heat required to heat water to produce steam from nuclear fission reactions (physical process) which entails the splitting of atoms of uranium in the nuclear reactor. The uranium fuel consists of small, hard ceramic pellets that are packaged in to long vertical tubes and are inserted into the reactor. The steam produced then turns turbines to produce electricity. Therefore the correct answer is C.
10. Nuclear fission reactions are physical processes that involves splitting of radioactive isotopes to form other stable atoms coupled with production of energy. Chemical reactions on the other hand are reactions involving rearrangements of atom structure to form other substances (products). Nuclear fission reactions are not affected by the environmental factors such as temperature while chemical reactions are affected by these changes, therefore increase in temperature affects chemical reactions but doesn't affect nuclear reactions. Therefore, the correct answer is A
