1.8 mol of Na. hope this helps
Answer:
a

b

Explanation:
From the question we are told that
The mass of the rock is 
The length of the small object from the rock is 
The length of the small object from the branch 
An image representing this lever set-up is shown on the first uploaded image
Here the small object acts as a fulcrum
The force exerted by the weight of the rock is mathematically evaluated as

substituting values


So at equilibrium the sum of the moment about the fulcrum is mathematically represented as

Here
is very small so
and 
Hence

=> 
substituting values


The mechanical advantage is mathematically evaluated as

substituting values


It is called weathering. there are three different types of weathering, physical weathering, chemical weathering, and biological weathering. Your particular question is caused by chemical weathering.
Answer:
N= 238 turns
Explanation:
The induced Emf that goes through a solenoid can be calculated using the below formula;
Where ξ=induced Emf
L= self inductance
I= current
ξ= L|dⁱ/dt|
Making L which is the self inductance subject of formula we have
L=ξ/[|dⁱ|*|dt|]
The current here is changing at the rate of
.0260 A/s
L=NΦB/i
N=ξ/Φ|di|*|dt|
Magnitude of the induced Emf given= 12.6mV then if we convert to volt we have 12.6×10⁻³ V
The current I = 1.40A
Magnitude flux through the flux=/0.00285 Wb
Then if we substitute all this Value to equation above we have
N=(12.6×10⁻³ V×1.40A)/(0.00285 Wb×0.0260 A/s)
N=238turn
Therefore, there are 238turns in the solenoid
Answer:
The answer is D. The electrons will flow from an area of high potential energy to an area of low potential energy.
X== low potential energy
Y = high potential energy
z = flow of electrons
Explanation: