I’m pretty sure u have it right
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Answer: True</h3>
For example, a very dense metal will sink to the bottom while something like wood will float on the surface. The wood is less dense compared to the water, which is why it floats. Density is the measure of how much stuff you can pack in a certain volume. The higher the density, the more stuff per volume. Think of it like packing a suitcase. If there's barely anything in there, then we can say its density is low. The more stuff crammed in the suitcase will increase the density (and therefore the weight), while keeping the volume the same.
Answer:
a)W= - 720 J
b)ΔU= 330 J
Explanation:
Given that
P = 0.8 atm
We know that 1 atm = 100 KPa
P = 80 KPa
V₁ = 12 L = 0.012 m³ ( 1000 L = 1 m³)
V₂ = 3 L = 0.003 m³
Q= - 390 J ( heat is leaving from the system )
We know that work done by gas given as
W = P (V₂ -V₁ )
W= 80 x ( 0.003 - 0.012 ) KJ
W= - 0.72 KJ
W= - 720 J ( Negative sign indicates work done on the gas)
From first law of thermodynamics
Q = W + ΔU
ΔU=Change in the internal energy
Now by putting the values
- 390 = - 720 + ΔU
ΔU= 720 - 390 J
ΔU= 330 J
If the object is in equilibrium that means that the sum of the forces on it is zero and the net force is zero. If none of the forces changes then the object continues in constant uniform motion. That means constant speed in a straight line.
