Answer:
Explanation:
Here we can use energy conservation
As per energy conservation conditions we know that work done by external source is converted into kinetic energy of the disc
Now we have
now we know that work done is product of force and displacement
so here we have
now for moment of inertia of the disc we will have
now from above equation we will have
Answer:
Option (B) is correct.
Explanation:
Given that the molecules of hydrogen gas () react with molecules of oxygen gas (
) in a sealed reaction chamber to produce water (
).
The governing equation for the reaction is
From the given, the only fact that can be observed that 2 moles of and 1 mole of
reacts to produce 2 moles of
.
As the mass of 1 mole of grams ... (i)
The mass of 1 mole of grams ...(ii)
The mass of 1 mole of grams (iii)
Now, the mass of the reactant = Mass of 2 moles of + mass 1 mole of
[ using equations (i) and (ii)]
grams.
Mass of the product = Mass of 2 moles of
[ using equations (iii)]
=36 grams
As the mass of reactants = mass of the product.
So, mass is conserved.
Hence, option (B) is correct.