Answer:

Explanation:
Considering the thermal conductivity of aluminium and brass as
and
respectively
The temperature at the end of aluminium and brass are given as
and
respectively with length of rod L=1.3 m , Length of aluminium
, length of brass
and letting temperature at steady state be T
At steady state, thermal conductivity of both aluminium and brass are same hence


Upon re-arranging




Therefore, the temperatures at which the metals are joined is 
Answer:
The ratio is
Explanation:
From the question we are told that
The radius of Phobos orbit is R_2 = 9380 km
The radius of Deimos orbit is 
Generally from Kepler's third law

Here M is the mass of Mars which is constant
G is the gravitational constant
So we see that 
=> ![[\frac{T_1}{T_2} ]^2 = [\frac{R_1}{R_2} ]^3](https://tex.z-dn.net/?f=%5B%5Cfrac%7BT_1%7D%7BT_2%7D%20%5D%5E2%20%3D%20%20%5B%5Cfrac%7BR_1%7D%7BR_2%7D%20%5D%5E3)
Here
is the period of Deimos
and
is the period of Phobos
So
![[\frac{T_1}{T_2} ] = [\frac{R_1}{R_2} ]^{\frac{3}{2}}](https://tex.z-dn.net/?f=%5B%5Cfrac%7BT_1%7D%7BT_2%7D%20%5D%20%3D%20%20%5B%5Cfrac%7BR_1%7D%7BR_2%7D%20%5D%5E%7B%5Cfrac%7B3%7D%7B2%7D%7D)
=> ![\frac{T_1}{T_2} = [\frac{23500 }{9380} ]^{\frac{3}{2}}]](https://tex.z-dn.net/?f=%5Cfrac%7BT_1%7D%7BT_2%7D%20%20%3D%20%20%5B%5Cfrac%7B23500%20%7D%7B9380%7D%20%5D%5E%7B%5Cfrac%7B3%7D%7B2%7D%7D%5D)
=>
The basic relationship between frequency and wavelength for light (which is an electromagnetic wave) is

where c is the speed of light, f the frequency and

the wavelength of the wave.
Using

and

, we can find the value of the frequency:
Answer:
Explanation:
Intensity of unpolarized light = I(o)
Intensity of light after first polarization by polarizer A. = I(o)/2
Angle between A and B = 120 degree.
Intensity of light after second polarization = I Cos² θ
= I(o) /2 x cos²120 = I(o) /8 .
Angle between B and C is 70 degree
Intensity of light after third polarization =
I(o)/8 x Cos² 70 = 0.1156 x I (o) /8 =
Required ratio =.01445
Answer:
The electric field inside the hollow plastic ball is zero.
Explanation:
According to Gauss's law, the electric field at the closed Gaussian surface
is given by

Now, to find the electric field inside the hollow plastic ball, we choose a spherical Gaussian surface inside the ball. And since all of the charge lies on the surface of the ball, the Gaussian surface does not enclose any charge; therefore, the Gauss's law gives:


The electric field inside the hollow plastic ball is zero.