Answer:
Now since mass of reactant is equal to mass of the product after the reaction so we can say that mass conservation is applicable here
Explanation:
As we know that zinc reacts with copper sulfate
so the reaction is given as

so here we have




Now total mass of reactant is given as

Mass of the product is given as

Now since mass of reactant is equal to mass of the product after the reaction so we can say that mass conservation is applicable here
Answer:

Explanation:
Radius of the pollen is given as

Volume of the pollen is given as



mass of the pollen is given as


so weight of the pollen is given as



Now electric force on the pollen is given



now ratio of electric force and weight is given as


Answer: The work is 1863 N*m
Explanation:
We can define work as:
W = F*d
Where F is the force that the mover needs to apply to the refrigerator, and d is the distance that the refrigerator is moved.
To move the refrigerator, the minimal force that the mover needs to do is exactly the friction force (In this case, the refrigerator will move with constant speed).
Then we will have:
F = 230 N
and the distance is 8.1 meters, then the work will be:
W = 230N*8.1 m = 1863 N*m
Well first of all, you must realize that it depends on how the jumpers are distributed on the earth's surface. If,say, one billion of them are in the eastern hemisphere and the other billion are in the western one, then the sum of all of their momenta could easily be zero, and have no effect at all on the planet. I'm pretty sure what you must have in mind is to consider the Earth to be a block, with a flat upper surface, and all the people jump in the same direction.
average mass per person = 60 kg.
jump velocity = 7 m/s straight up and away from the block, all in the same direction
one person's worth of momentum = (m) (v) = 420 kg.m/s
sum of two billion of them = 8.4 x 10¹¹ kg-m/s all in the same direction
Earth's "recoil" momentum = 8.4 x 10¹¹ in the opposite direction = (m) (v)
Divide each side by 'm' : v = (momentum) / (mass) =
The Earth's "recoil" velocity is (8.4 x 10¹¹) / (5.98 x 10²⁴) =
1.405 x 10⁻¹³ m/s =
<em> 0.00000000014 millimeter per second
</em>I have no intuitive feeling for this kind of thing, so can't judge whether
the answer is reasonable. But my math and physics felt OK on the
way to the solution, so that's my answer and I'm sticking to it.
Answer:

The Andromeda is a galaxy which is nearest to the milky way. It is also named as Messier 31 or M31 or NGC 224. It is a spiral galaxy located at a distance of approximately 2.5 million light years from earth.
another name Andromeda in Hindi is Vaikunth.