Answer:
E = 401.3 eV
Explanation:
As we know that the thinnest gap in the direction of metal is given as

so here we can say that lowest energy of photon will not able to break this electron from above thickness
so we will have

here we have

also we have

so we will have


Answer:
0.86 m/s
Explanation:
A = cross-sectional area of the duct = 900 cm² = 900 x 10⁻⁴ m²
v = speed of air in the duct
t = time period of circulation = 40 min = 40 x 60 sec = 2400 sec
V = Volume of the air in the room = volume of room = 7 x 11 x 2.4 = 184.8 m³
Volume of air in the room is given as
V = A v t
inserting the values
184.8 = (900 x 10⁻⁴) (2400) v
v = 0.86 m/s
If you're careful, you ought to be able to observe ANY of these properties
without any effect on the substance:
Absorption, albedo, angular momentum, area, color, concentration,
density, elasticity, electric charge, electrical conductivity, flow rate,
electrical impedance, electric potential, fluidity, length, location, mass,
luminance, luminescence, luster, magnetic field, momentum, opacity,
permeability, permittivity, plasticity, pressure, radiance, solubility, spin,
specific heat, resistivity, reflectivity, refractive index, temperature,
thermal conductivity, velocity, viscosity, or volume.