The mass of ore required is
21 700 t.
r = 750 cm
V =

=

= 1.767 × 10⁹ cm³
The density of lead is 11.34 g/cm³.
So mass of lead sphere = 1.767 × 10⁹ cm³ ×

= 2.004 ×10¹⁰ g
2.004 ×10¹⁰ g ×

= 2.004 × 10⁷ kg
2.004 × 10⁷ kg ×

= 2.004 × 10⁴ t
92.5% efficiency means 92.5 t Pb per 100 t of ore.
Mass of ore = 2.004 × 10⁴ t Pb ×

= 2.17 × 10⁴ t ore = 21 700 t ore
Answer: The molarity of KBr in the final solution is 1.42M
Explanation:
We can calculate the molarity of the KBr in the final solution by dividing the total number of moles of KBr in the solution by the final volume of the solution.
We will first calculate the number of moles of KBr in the individual sample before mixing together
In the first sample:
Volume (V) = 35.0 mL
Concentration (C) = 1.00M
Number of moles (n) = C × V
n = (35.0mL × 1.00M)
n= 35.0mmol
For the second sample
V = 60.0 mL
C = 0.600 M
n = (60.0 mL × 0.600 M)
n = 36.0mmol
Therefore, we have (35.0 + 36.0)mmol in the final solution
Number of moles of KBr in final solution (n) = 71.0mmol
Now, to get the molarity of the final solution , we will divide the total number of moles of KBr in the solution by the final volume of the solution after evaporation.
Therefore,
Final volume of solution (V) = 50mL
Number of moles of KBr in final solution (n) = 71.0mmol
From
C = n / V
C= 71.0mmol/50mL
C = 1.42M
Therefore, the molarity of KBr in the final solution is 1.42M
An electromagnet is a device in which, by electric current, the magnetic field is produced. Increase the number of coils and increase the strength of the current, thus, increasing the strength of an electromagnet.
The correct option is B.
<h3>What is an electromagnet?</h3>
An electromagnet is a device that consists of a magnetic core encircled by a coil, through which an electric current is carried to magnetize the core.
Wherever controllable magnets are required, such as in devices where the magnetic flux must be adjusted, reversed, or switched on and off, an electromagnet is utilized.
Thus, the correct option is B, increasing the number of coils and increasing the strength of the current.
Learn more about electromagnet, here:
brainly.com/question/13803241
C.
D.
E.
These should be the main reasons. As Pluto was mainly categorized in dwarf planet for not being able to satisfy the last statement which states that it should have a fixed neighbourhood with other planets.
Answer:
Explanation:
We know that momentum is the product of mass and velocity so here
mass (m) = 1700 kg
velocity (v) = 13 m/s
So now
momentum = m * v
= 1700 * 13
= 22100 kg m/s
hope it helps :)