Answer: 29.50 m
Explanation: In order to calculate the higher accelation to stop a train without moving the crates inside the wagon which is traveling at constat speed we have to use the second Newton law so that:
f=μ*N the friction force is equal to coefficient of static friction multiply the normal force (m*g).
f=m.a=μ*N= m*a= μ*m*g= m*a
then
a=μ*g=0.32*9.8m/s^2= 3.14 m/s^2
With this value we can determine the short distance to stop the train
as follows:
x= vo*t- (a/2)* t^2
Vf=0= vo-a*t then t=vo/a
Finally; x=vo*vo/a-a/2*(vo/a)^2=vo^2/2a= (49*1000/3600)^2/(2*3.14)=29.50 m
<h2>Answer with Explanation </h2>
Dalton’s theory can be classified by the following hypotheses:
1) All material was formed of particles, unbreakable and strong construction segments.
2) All particles of a given component are indistinguishable in volume and characteristics
3) Compounds are determined by a mixture of two or more distinct kinds of atoms.
4) Chemical responses appeared in the rearrangement of the reacting atoms.
This theory was to explain all matter in terms of atoms and their characteristics, the law of conservation of volume and the law of constant composition.
If this case could ever happen, the speed would follow from this formula:

with f the frequency and lambda the wavelength. We are give a wavelength of 10m. The frequencies of the visible light can range between 400 to about 790 Terahertz, so let us pick a middle point of 600 THz ("green-ish") as a "representative."

The speed of such a wave would have to be 6e+15 m/s (which would be 7 orders of magnitude higher than the universal speed of light constant)
If i was feeling harsh today, I'd say the answer to your question is impossible to obtain due to the fact that photons do not emit radiation, photons ARE the radiation emitted. Though for the sake of it, here is the method...
<u>The simple method:
</u>
E=hf
therefore f=e/h
f=(3.611x10^-15) / 6.63x10^-34)
Answer: 5.45x10^18