Answer:
E = h f = h c / λ energy of single photon
n E = 4.00E-11 W/m^2 energy required for visibility
n h c / λ = 4.00E-11 number of photons required for visibility (per square meter)
n = 4.00E-11 * 5.00E-7 / (6.63E-34 * 3.00E8)
n = 20.0E-18 / 19.9 E-26 = 1.00E8
100 million photons would be required on 1 m^2 to create visibility
a / A = π * (3.6E-3)^2 / 1 = 4.07E-5 fraction of area available
4.07E-5 * 1.00E8 = 4.07E3 photons required
Answer:
Kinetic energy does not stay the same at all heights
Explanation:
Well as the height and wind increase so does the kinetic energy it's like when you fall as you are about to hit the floor you speed increases
HOPE THIS HELPS YA :)
B is correct. Ever wondered why ice floats in water?
Explanation:
Trains that use magnetic levitation (maglev) are suspended above the track, which greatly reduces friction from the rails and allows the trains to travel between 250 and 300 miles per hour! Magnetic levitation uses attractive and repulsive magnetic forces to suspend and control the speeds and motion of the trains.
