When an object turns around an internal axis (like the Earth turns around its axis) it is called a rotation. When an object circles an external axis (like the Earth circles the sun) it is called a revolution.
PART A)
Electrostatic potential at the position of origin is given by

here we have



now we have


Now work done to move another charge from infinite to origin is given by

here we will have

so there is no work required to move an electron from infinite to origin
PART B)
Initial potential energy of electron




Now we know



now by energy conservation we will have
So here initial total energy is sufficient high to reach the origin
PART C)
It will reach the origin
To be considered a source of water pollution, the source must include a chemical is false.
<u>Explanation:
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The water pollution may be caused either by chemicals or waste materials that doesn’t contain chemicals such as domestic wastes, organic compounds, heavy metals etc. The life on Earth mostly relies on water and air, and if these two gets polluted; the results will be dangerous.
Around 70% of the planet is covered with water and the present state of its purity is a matter of a serious thought. Looking over various pollutants, only chemical wastes are not responsible to pollute the water.
Instead, there is range of elements from plastic scraps to chemical wastes that comes from either the non-point sources or the point sources. There are organic waste materials, heavy metals, volcanic eruptions, Tsunamis, earthquakes, etc. are also responsible to contaminate water and affect the amphibians as well as humans.
Hello,
Your answer to this problem is 400/3
Hope this helps!
Answer:
(A) No
(B) Speed decreases
Explanation:
(A) since there is nothing propelling the boat and the friction between the ice and the boat and also air resistance is negligible the net force of the system in the horizontal direction is zero and hence there is no change in the horizontal momentum of the boat.
(B) Since the person had not velocity in the horizontal direction before landing on the boat but now has one after landing on the boat, the speed of the boat will decrease because the momentum has to be conserved (remember there is no change in it).