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A flat water surface at temperature $T = 20^\circ\text{C} = 293,\text{K}$ evaporates into a vacuum.

The system consists of a set of DC circuits containing batteries, resistors with given resistances in kilohms, and photoelements.

A car moves on a horizontal road from rest under the action of an engine delivering constant power $W$ in watts.

The system consists of two open vessels connected at the bottom by a narrow horizontal tube filled with water.

A satellite moves in a circular low Earth orbit at altitude $h = 300,\text{km} = 3.

A stream of water forms identical spherical droplets of radius $a$ and density $\rho$.

Two beads of masses $m_1$ and $m_2$ move without friction on a fixed rigid circular wire of circumference $L$.

A rigid spherical spacecraft of radius $R$ and mass $m$ is placed in a uniform поток of solar radiation.

The system consists of a car moving with rolling wheels of diameter $D = 1,\text{m}$, filmed by a camera and projected onto a screen at a rate of $f = 8,\text{frames/s}$.

A piece of iron of mass $M$ is acted upon by two blacksmiths.

Two identical vertical cylinders contain water and are connected by a horizontal tube filled with the same incompressible fluid of density $\rho$.

Two point masses $m_1$ and $m_2$, with units kilograms, lie on a horizontal frictionless plane and are connected by a light spring with stiffness $c$ measured in $\mathrm{N,m^{-1}}$.

The system consists of a real voltage source with electromotive force $\mathcal{E} = 20,\text{V}$ and internal resistance $r = 20,\Omega$, connected to an external heater assembled from four thin wire…

A long rigid rod $AB$ is connected at end $A$ to a vertical screw by a threaded hole.

A rigid horizontal rod $O_1A$ of length $l$ rotates with constant angular velocity $\Omega$ about a fixed vertical axis through $O_1$.

The solution depends entirely on the topology of the circuit in Figure 4, since the potential difference between points $C$ and $D$ is determined by the specific arrangement of sources and resistors.