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Suction is the day-to-day term for the movement of gases or liquids along a pressure gradient with the implication that the movement occurs because the lower pressure pulls the gas or liquid. However, the forces acting in this case do not originate from just the lower pressure side, but also from the side of the higher pressure, as a reaction ...
Ultra-high vacuum chambers, common in chemistry, physics, and engineering, operate below one trillionth (10 −12) of atmospheric pressure (100 nPa), and can reach around 100 particles/cm 3. [4] Outer space is an even higher-quality vacuum, with the equivalent of just a few hydrogen atoms per cubic meter on average in intergalactic space.
Slab suction is weaker than slab pull, which is the strongest of the driving forces. When measuring the forces of these two mechanisms, slab pull in subducting plate boundaries for upper mantle slabs is 1.9 × 10^21 N. [clarification needed] In comparison slab suction in the upper and lower mantle totaled 1.6 × 10^21 N. [3]
Fire engine drafting. A draft is the use of suction to move a liquid such as water from a vessel or body of water below the intake of a suction pump.A rural fire department or farmer might draft water from a pond as the first step in moving the water elsewhere.
Slab pull is a geophysical mechanism whereby the cooling and subsequent densifying of a subducting tectonic plate produces a downward force along the rest of the plate. In 1975 Forsyth and Uyeda used the inverse theory method to show that, of the many forces likely to be driving plate motion, slab pull was the strongest. [1]
The SI unit of force is the newton (symbol N), which is the force required to accelerate a one kilogram mass at a rate of one meter per second squared, or kg·m·s −2.The corresponding CGS unit is the dyne, the force required to accelerate a one gram mass by one centimeter per second squared, or g·cm·s −2. A newton is thus equal to ...
The force required to detach an ideal suction cup by pulling it directly away from the surface is given by the formula: = where: F is the force, A is the area of the surface covered by the cup, P is the pressure outside the cup (typically atmospheric pressure) This is derived from the definition of pressure, which is:
The compressive forces may also be applied in multiple directions; for example inwards along the edges of a plate or all over the side surface of a cylinder, so as to reduce its area (biaxial compression), or inwards over the entire surface of a body, so as to reduce its volume.