Answer:
Explanation:
This is a simple Law of Momentum Conservation problem of the inelastic type. The equation for this is
![[m_1v_1+m_2v_2]_b=[(m_1+m_2)v]_a](https://tex.z-dn.net/?f=%5Bm_1v_1%2Bm_2v_2%5D_b%3D%5B%28m_1%2Bm_2%29v%5D_a)
Filling in:
![[1200(4.5)+2100(0)]=[(1200+2100)v]](https://tex.z-dn.net/?f=%5B1200%284.5%29%2B2100%280%29%5D%3D%5B%281200%2B2100%29v%5D)
which simplifies to
5400 + 0 = 3300v
so v = 1.6 m/s to the east, choice B
Answer:
Light
Explanation:
The way a concave mirror works is that since it's concave, the light bounces off of each other. a convex mirror, it curved the opposite, and the mirror has no way to bounce off of itself.
Answer:
It is<em> impossible</em> to construct a machine which produces the <em>work output greater than the work input.</em>
Let us consider the II law of thermodynamics.
According to Kelvin Plank's statement any engine/machine does not give hundred percent efficiency. And violating the PMM-II(Perpetual motion of machine II kind), Always some amount of energy transferred to the sink or surroundings.
Therefore
W(ouput) = Q₁-Q₂
There are many reasons to lower the work output, just for an example friction between the mating parts reduces the work output.
Answer:
The diameter of the hole increases
Explanation:
Metals expand and contract with temperature. Whenever metal is heated, it usually expands in relation to its thermal expansivity. This expansion leads to a slight increase in surface area.
Once the surface area of the metal changes, this means that the dimensions of the whole metal surface changed. As a result, the diameter of the hole drilled in the metal plate will change also. In our case, the diameter of the hole will increase.
Question:
The water molecules now in your body were once part of a molecular cloud. Only about onemillionth of the mass of a molecular cloud is in the form of water molecules, and the mass density of such a cloud is roughly 2.0×10−21 g/cm^3.
Estimate the volume of a piece of molecular cloud that has the same amount of water as your body.
Answer:
The volume of cloud that has the same density as the amount of water in our body is 1.4×10²⁵ cm³
Explanation:
Here, we have mass density of cloud = 2.0×10⁻²¹ g/cm^3
Density = Mass/Volume
Volume = Mass/Density = If the mass is 40 kg and the body is made up of 70% by mass of water, we have
28 kg water = 28000 g
Therefore the Volume = 28 kg/ 2.0×10⁻²¹ g/cm^3 = 1.4×10¹⁹ m³ = 1.4×10²⁵ cm³.
Therefore, the volume of cloud that has the same density as the amount of water in our body = 1.4×10²⁵ cm³.
