Answer:
3.066×10^21 photons/(s.m^2)
Explanation:
The power per area is:
Power/A = (# of photons /t /A)×(energy / photon)
E/photons = h×c/(λ)
photons /t /A = (Power/A)×λ /(h×c)
photons /t /A = (P/A)×λ/(hc)
photons /t /A = (680)×(678×10^-9)/(6.63×10^-34)×(3×10^-8)
= 3.066×10^21
Therefore, the number of photons per second per square meter 3.066×10^21 photons/(s.m^2).
Answer:
C)T
Explanation:
The period of a mass-spring system is:

As can be seen, the period of this simple harmonic motion, does not depend at all on the gravitational acceleration (g), neither the mass nor the spring constant depends on this value.
Answer:
Explanation:
Density = Mass / Volume = 850 / 40*10*5 = 0.425 g /cm^3
Answer:
The forces that do non-zero work on the block are gravity and normal reaction force
Explanation:
Position of B :
x = 4.66*cos 30 = 4.036
y = 3-4.66*sin 30 = 3-2.33 = 0.67
BC = √y^2+(x-1)^2 = √0.67^2+3.036^2 = 3.109
heading = arctan y/(x-1) = arctan 0.67/(3.036) = 12.44° south of west
hope this helps :)