Answer:
Resistor
Explanation:
Resistor provides resistance to the flow of electric current in a circuit.
It controls the amount of current in a circuit by acting as a barrier to the flow of electric charges
It is b! the lithosphere is the crust and upper mantle
I think it is C because it makes more sense
Answer:2 ft/s
Explanation:
Given
Length of Pole is 9 ft
Length of Joe is 3 ft
Joe walks away from Pole at the rate 4 ft/s
Let Joe is x m away from Pole so its shadow length is x'
From Similar triangle concept

3x'=x+x'
x=2x'
and it is given 
Differentiating


