Answer:
<em>The Sun produces energy by the process of nuclear fusion. Nuclear fusion occurs when lighter nuclei combine to produce a larger, heavier nucleus. In the process, energy is released. Nuclear fusion requires very high temperatures and pressures. Nuclear fusion occurs in the core of the Sun when hydrogen atoms combine to form helium atoms.</em>
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<em>Sample Response: The Sun produces energy by the process of nuclear fusion. Nuclear fusion occurs when lighter nuclei combine to produce a larger, heavier nucleus. In the process, energy is released. Nuclear fusion requires very high temperatures and pressures. Nuclear fusion occurs in the core of the Sun when hydrogen atoms combine to form helium atoms</em>
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Answer:
mass conservation is valid for all closed system where the mass will remain in the system always
Explanation:
Conservation of mass is applicable everywhere in classical physics
Here we can also apply mass conservation as we know that the initially the beaker and its water content is having total mass of 109.44 g

now when we heated it to higher temperature then its total mass will be lesser than the initial mass this is because some of the water may evaporate from the system.
Here if we repeat the same experiment with closed boundary then we can see that total mass will be conserved
So here mass conservation is valid for all closed system where the mass will remain in the system always
Answer: The two answers are the machine will require an input greater than 100 ft.-lbs. And the other is The machine may accomplish the task faster than manual work.
Hope this help :3
The first thing you should know for this case is that density is defined as the quotient between mass and volume.
d = m / v
We have two states:
State 1:
d1 = 1.20 g / l
v1 = 1.02 × 106 l
State 2:
v2 = 1.09 × 106 l
Since the mass remains constant, then:
m = d1 * v1
Then, the density in state two will be:
d2 = m / v2
Substituting the value of the mass we have:
d2 = (d1 * v1) / v2
Substituting the values:
d2 = ((1.20) * (1.02 * 10 ^ 6)) / (1.09 * 10 ^ 6) = 1.12 g / l
answer:
The density of the heated air in the balloon is 1.12 g / l