The cost of the electricity if 42000 kWh of electricity is used is ; $1680
<h3>Determine the cost of electricity </h3>
<u>Given that ;</u>
value of electricity used = 42000 kWh
cost rate of electricity = $0.04/kWh
Final step : Determine the total cost of electricty used
unit cost = $0.04/kWh
Totals cost = unit cost * value of electricity used
= 0.04 * 42000 = $1680
Hence we can conclude that The cost of the electricity if 42000 kWh of electricity is used is ; $1680.
Learn more about Electricity cost : brainly.com/question/14277272
A force of 8 N will be required.
<h3><u>Explanation:</u></h3>
Mechanical advantage is defined as the ratio of output force from a system to the input force into the system. A machine which has the mechanical advantage more than 1 means it requires less force to give more force as output. Similarly, when the mechanical advantage for the machine is less than 1,it means more force is required to give to achieve a less one.
Here in the question, the mechanical advantage of the pulley is 2.
Output force required to pull the sack of potatoes upto kitchen is 16N.
Mechanical advantage = Output force / input force.
Or, 2= 16 / input force.
So input force = 
So a force of 8 N will be required to pull the pulley.
Answer:
There are four steps in solving a stoichiometry problem:
Write the balanced chemical equation.
Convert the units of the given substance (A) to moles.
Use the mole ratio to calculate the moles of wanted substance (B).
Convert moles of the wanted substance to the desired units.
Explanation:
(https://socratic.org/questions/how-to-solve-the-problems-of-stiohiomerty-what-is-the-formula-of-stiohiomerty) This site will give you all the info you need on how to solve it! Gives examples too!
Protons- these have a positive charge
Electrons-negative charge
Neutrons- neutral charge