Dvanced photodiode detectors have a second light-emitting diode, operating at a wavelength of 2.0 × 10–7 m, to detect even smaller smoke particles from smoldering flames. what is the frequency difference between the two light beams?

Explanation:

The relationship between wavelength and frequency is given by:

where

is the speed of light

f is the frequency

is the wavelength

In this problem, we know the wavelength:

So we can re-arrange the formula above to find the frequency:

the minimum constant speed at which she can catch the train is 2.7 m/s

given:

acceleration = 0.6

time = 4.5 s

to find:

velocity = ?

formula used:

from 1st kinematic equation we get,

v = u + at

u = initial speed of train = 0 m/s

v = final speed of the train

a = acceleration of the train

t = time

solution:

from 1st kinematic equation we get,

v = u + at

u = initial speed of train = 0 m/s

v = final speed of the train

a = acceleration of the train

t = time

v = 0 + (0.6 × 4.5)

v = 2.7 m/s

the minimum constant speed at which she can catch the train is 2.7 m/s