Finding frequency of light(simple physics)

AI Thread Summary
The discussion centers on calculating the frequency of light with a wavelength of 650 nm using the formula c = λf, where c is the speed of light. The user calculated the frequency as 4.62 x 10^14 Hz, while the book lists the answer as 10^16 Hz. The user converted the wavelength from nanometers to meters correctly, leading to the conclusion that their answer is accurate. The consensus is that the user’s calculation is correct and the book's answer is likely incorrect. The discussion highlights the importance of careful unit conversion in physics calculations.
eax
Messages
61
Reaction score
0
I got my answer but its not the same as the one in my book. My answer is 4.62*10^14 the book is same thing but *10^16. Heres the details

Wave length of 650nm is traveling through a vacuum(speed of light). what I did is took this formula

c(lightspeed = 3*10^8m/s)=l(wavelength)*f(frequency)

I did this
Code:
c(lightspeed = 3*10^8)=L(wavelength)*f(frequency)
---------------------------------------------------------------------
L

thus leaves with 
c
-- = f
L

filling in the variables c is constant so I want bother with that
3*10^8
--------------- = f
650*10^-9(convert to m from nm)
what I got is f = 4.62*10^14

Am I right and the book is wrong. Because for all 4 questions the answer the book gives ends with 10^16 and I get 10^14.


Thank you for helping !
 
Physics news on Phys.org
Thank you for you quick reply. The question(s) were driving me crazy.
 
TL;DR Summary: I came across this question from a Sri Lankan A-level textbook. Question - An ice cube with a length of 10 cm is immersed in water at 0 °C. An observer observes the ice cube from the water, and it seems to be 7.75 cm long. If the refractive index of water is 4/3, find the height of the ice cube immersed in the water. I could not understand how the apparent height of the ice cube in the water depends on the height of the ice cube immersed in the water. Does anyone have an...
Thread 'Variable mass system : water sprayed into a moving container'
Starting with the mass considerations #m(t)# is mass of water #M_{c}# mass of container and #M(t)# mass of total system $$M(t) = M_{C} + m(t)$$ $$\Rightarrow \frac{dM(t)}{dt} = \frac{dm(t)}{dt}$$ $$P_i = Mv + u \, dm$$ $$P_f = (M + dm)(v + dv)$$ $$\Delta P = M \, dv + (v - u) \, dm$$ $$F = \frac{dP}{dt} = M \frac{dv}{dt} + (v - u) \frac{dm}{dt}$$ $$F = u \frac{dm}{dt} = \rho A u^2$$ from conservation of momentum , the cannon recoils with the same force which it applies. $$\quad \frac{dm}{dt}...
Back
Top