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:
C) gravity separated from the unified force, strong force separated from the unified force, inflationary expansion occurred, electromagnetic and weak forces separated from the unified force, quarks and electrons formed
Answer:
The system is still balanced
Explanation:
If we suppose that the boy weights M and the girl m, and are balanced at distances L1 and L2 from the pivot point respectively, thy will be balanced if the resultant torque of all the farces from the pivot pint is cero:
(1)
now they moved to distances (L1)/2 and (L2)/2, the resultant torque will be:
(2)
1/2 can be taken out as a common factor:
(3)
As the the inside of the parenthesis equals equation (1) that equals zero, hte whole equiation equals zero:
(3)
So the system is still balanced
Answer:
See below
Explanation:
Vertical position = 45 + 20 sin (30) t - 4.9 t^2
when it hits ground this = 0
0 = -4.9t^2 + 20 sin (30 ) t + 45
0 = -4.9t^2 + 10 t +45 = 0 solve for t =4.22 sec
max height is at t= - b/2a = 10/9.8 =1.02
use this value of 't' in the equation to calculate max height = 50.1 m
it has 4.22 - 1.02 to free fall = 3.2 seconds free fall
v = at = 9.81 * 3.2 = 31.39 m/s VERTICAL
it will <u>also</u> still have horizontal velocity = 20 cos 30 = 17.32 m/s
total velocity will be sqrt ( 31.39^2 + 17.32^2) = 35.85 m/s
Horizontal range = 20 cos 30 * t = 20 * cos 30 * 4.22 = 73.1 m
