Search results
Results from the WOW.Com Content Network
This is often the case for water on bare metallic or ceramic surfaces, [15] although the presence of an oxide layer or contaminants on the solid surface can significantly increase the contact angle. Generally, if the water contact angle is smaller than 90°, the solid surface is considered hydrophilic [16] and if the water contact angle is ...
For a water-filled glass tube in air at standard conditions for temperature and pressure, γ = 0.0728 N/m at 20 °C, ρ = 1000 kg/m 3, and g = 9.81 m/s 2. Because water spreads on clean glass, the effective equilibrium contact angle is approximately zero. [4] For these values, the height of the water column is
An accelerometer measures proper acceleration, which is the acceleration it experiences relative to freefall and is the acceleration felt by people and objects. [2] Put another way, at any point in spacetime the equivalence principle guarantees the existence of a local inertial frame, and an accelerometer measures the acceleration relative to that frame. [4]
This force is related to the contact angle by the following equation: cos θ = F − F b I σ , {\displaystyle \cos \theta ={\frac {F-F_{\text{b}}}{I\sigma }},} where F is the total force measured by the force meter, F b is the force of buoyancy due to the solid sample displacing the liquid, I is the wetted length, and σ is the known ...
Here is a picture of a water droplet on a lotus leaf. If the temperature is 20 o then λ c {\displaystyle \lambda _{c}} = 2.71mm The capillary length or capillary constant is a length scaling factor that relates gravity and surface tension .
In petroleum engineering, the Leverett J-function is a dimensionless function of water saturation describing the capillary pressure, [1] = / where is the water saturation measured as a fraction, is the capillary pressure (in pascal), is the permeability (measured in m²), is the porosity (0-1), is the surface tension (in N/m) and is the contact angle.
Angular acceleration has physical dimensions of angle per time squared, measured in SI units of radians per second squared (rad ⋅ s-2). In two dimensions, angular acceleration is a pseudoscalar whose sign is taken to be positive if the angular speed increases counterclockwise or decreases clockwise, and is taken to be negative if the angular ...
where n is the index of refraction of the medium in which the lens is working (1.00 for air, 1.33 for pure water, and typically 1.52 for immersion oil; [1] see also list of refractive indices), and θ is the half-angle of the maximum cone of light that can enter or exit the lens. In general, this is the angle of the real marginal ray in the