Answer:
??? i don't no what you just said
Explanation:
The text does not specify whether the resistance R of the wire must be kept the same or not: here I assume R must be kept the same.
The relationship between the resistance and the resistivity of a wire is

where

is the resistivity
A is the cross-sectional area
R is the resistance
L is the wire length
the cross-sectional area is given by

where r is the radius of the wire. Substituting in the previous equation ,we find

For the new wire, the length L is kept the same (L'=L) while the radius is doubled (r'=2r), so the new resistivity is

Therefore, the new resistivity must be 4 times the original one.
Answer:
i)20369 photons
ii) 40 ps
Explanation:
Momentum of one Sodium atom:

In other to stop it, it must absorb the same momentum in photons:

Now, for the minimun time, we use the speed of light and the wavelength. For the n photons:

Answer:
The angular velocity is 
Explanation:
From the question we are told that
The mass of each astronauts is 
The initial distance between the two astronauts 
Generally the radius is mathematically represented as 
The initial angular velocity is 
The distance between the two astronauts after the rope is pulled is 
Generally the radius is mathematically represented as 
Generally from the law of angular momentum conservation we have that

Here
is the initial moment of inertia of the first astronauts which is equal to
the initial moment of inertia of the second astronauts So

Also
is the initial angular velocity of the first astronauts which is equal to
the initial angular velocity of the second astronauts So

Here
is the final moment of inertia of the first astronauts which is equal to
the final moment of inertia of the second astronauts So

Also
is the final angular velocity of the first astronauts which is equal to
the final angular velocity of the second astronauts So

So

=> 
=> 
=> 
=> 
Answer:
Weight of the woman in Newton

Mass of the woman in slug

Mass of the woman in kg

My weight in Newton

Explanation:
From the question we are told that
The weight of the woman in pounds is 
Converting to Newton
1 N = 0.22472 lb
x N = 157
=> 
=> 
Obtaining the mass in slug

Here 
So


Obtaining the mass in kilogram

Here 
So


Generally weight is mathematically represented as

Given that my mass is 80 kg then my weight is

