low speed means non relativistic.
the velocities relative to an observer outside the train are added.
51 m/s.
Were ita light wave, rather than Emma, the speed wold not depend on the speed of the train. Though that may sound surprising, I think it's true. Special relativity says more about this.
Special relativity "shows up" when the speeds get very high indeed.
Answer:
An object moves at a constant speed of 6m/s. this means that the object moves 6 meters every second
Explanation:
Answer:
b. AG, work function=4.74eV
Explanation:
Ultraviolet light starts at the end of the visible light spectrum, where violet light ends:
(wavelength of lowest-energy ultraviolet light)
So, the lowest energy of ultraviolet light can be found by using the formula
where
h is the Planck constant
c is the speed of light
Substituting,
And keeping in mind that
This energy converted into electronvolts is
The work function of a metal is the minimum energy needed to extract a photoelectron from the surface of the metal. Therefore, the metals that exhibit photoelectric effect are the ones whose work function is larger than the energy we found previously, so:
b. AG, work function=4.74eV
Because for all the other metals, visible light will be enough to extract photoelectrons.