Question

I have some doubts in physics!

Answer 1

Q1) The de broglie wavelength of a body moving with speed V is lambda
on its way it loses some of its mass and gains twice the speed
KE also increases to twice of its initial value
what will be the new debroglie wavelength?

Attempt:
Initially..
\[\Large KE=\frac{1}{2}m v^2\]
Later..\[\Large 2KE=\frac{1}{2}M'(2v)^2\]
Divide 1/2
\[\Large M'=\frac{m}{2}\]
Initially..also..
\[\Large\lambda = \frac{h}{mv}\]
\[\Large \lambda ' = \frac{h}{\frac{m}{2}v}=2 \lambda\]
But the answer is remains same..what did I do wrong?

Answer 2

Q2)

Trace the path of a ray of light passing through a glass prism(ABC) as shown in the figure.If the refractive index of glass is root ,find out the value of angle of emergence from the prism.
I don't know how to approach this question..

Answer 3

Q3)
http://i.imgur.com/m6Kdm5u.png
How does the balancing length change(increase,decrease or remains same) if:
A)R is decreased.
B)S is increased.

Answer 4

@Mashy

Answer 5

@Vincent-Lyon.Fr

Answer 6

1) very last line v should be 2v

Answer 7

2) Since the light is approaching the edge of the prism at a right-angle (i.e. normal to the edge), there will be no refraction. I am unsure from the diagram, but it looks like it goes out of the edge AB, where there'll be some refraction. If it's going from a higher refractive index to a lower one (e.g. glass to air) the angle from the line normal to the surface will increase. Like this: https://upload.wikimedia.org/wikipedia/commons/5/5d/RefractionReflextion.svg.

Also
\[\frac{\sin\theta_1}{\sin\theta_2}=\frac{n_2}{n_1}\]

Answer 8

Link doesn't work: remove the dot at the end

Answer 9

It lost half its mass and inceased to twice its speed, keeping momentum the same.

Answer 10

what about the 3rd one??

Answer 11

ur last equation u have to plug 2v , not v !

Answer 12

yes got that mistake ! 2nd and 3rd?

Answer 13

since its perpendicular incidence, the ray of light goes straight throu and gets incident on the side AB.. now you can do some geometry and calculate what is the angle of incidence!..