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:
682.32 m
Explanation:
Speed of the passing speeder = 120 km/hr = 120 × 0.2777 = 33.33 m/s
time after which police man starts = 2 seconds
Acceleration of the policeman = 4.0 m/s²
let the time taken to catch be 't' seconds
Now,
The total distance to be covered by the policeman
= Distance covered by the speeder in the 2 seconds + Distance further traveled by the speeder in time t
thus,
From Newton's equation of motion
where,
s is the total distance traveled by the police man
u is the initial speed = 0
a is the acceleration
t is the time
thus,
= 33.33 × 2 + 33.33 × t
or
2t² = 66.66 + 33.33t
or
2t² - 33.33t - 66.66 = 0
on solving the above equation, we get
t = 18.47 seconds (negative value is ignored as time cannot be negative)
therefore,
the total distance covered = 33.33 × 2 + 33.33 × 18.47 = 682.32 m
Volcanoes: Most volcanoes are formed by the movement of tectonic plates<span> on the surface of the earth. These plates basically float on mantle. Sometimes these plates will sink into the mantle. The rock becomes so hot it melts. Gradually, the molten rock (the melted rock) will then make it's way back up. When it surfaces it, we call it "lava". As lava layers, it slowly forms a volcano.
Valleys: Basically formed by a river valley. The stream shapes the Earth's crust over time into a funnel-like v-shape or u-shape (depending on the flow of the stream).
Mountains: When plates collide and through pressure start building up into a cone shape.</span>
WHICH wax he tries out is the independent variable.
How clean his car stays is the dependent variable.
