Answer:
The total applied force on the trolley is 5 N toward the North.
Explanation:
In this problem, Ben is pushing the trolley to north and Gary is pushing it to south. So both the forces are acting 180° opposite to each other. As force is a vector quantity, the net force or total force acting on any object should be calculated by vector addition of number of forces along with their directions. So in this case, if we consider the force Ben is applying as F1 and the force Gary is applying as F2 on the trolley. Then the net or total force acting on the trolley will be 
. This is because, F1 and F2 are acting opposite to each other in direction.Thus, 
.
So the total force acting on the trolley is 5 N and it is toward the north direction.
Answer:
ΔH = 2.68kJ/mol
Explanation:
The ΔH of dissolution of a reaction is defined as the heat produced per mole of reaction. We have 3.15 moles of the solid, to find the heat produced we need to use the equation:
q = m*S*ΔT
<em>Where q is heat of reaction in J,</em>
<em>m is the mass of the solution in g,</em>
<em>S is specific heat of the solution = 4.184J/g°C</em>
<em>ΔT is change in temperature = 11.21°C</em>
The mass of the solution is obtained from the volume and the density as follows:
150.0mL * (1.20g/mL) = 180.0g
Replacing:
q = 180.0g*4.184J/g°C*11.21°C
q = 8442J
q = 8.44kJ when 3.15 moles of the solid react.
The ΔH of the reaction is:
8.44kJ/3.15 mol
= 2.68kJ/mol
10) Arsenic is a chemical agent which was used in preserving dead bodies in the past. It is mainly a formaldehyde mixture with coloring agents to give a dead body the look of life. Sylvester was a third mummy that was embalmed with arsenic in the late 1800s and is now on exhibit at Ye Olde Curiosity Shop in Seattle, Washington. His mummified body showed an extremely unusual since the remains weighed approximately 80 lbs when a body is composed of 70-80% water, after dehydration, the weight should be about 20-30% the premortem weight. The solution was also used during Civil War to preserve dead bodies <span>as the dead were being shipped home from the battlefield.
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9) R<span>esearch can yield dates when certain plants/animals became domesticated and entered the standard diets of people, meaning you would not see masses eating beef before the cow became domesticated. To further this you can look at when a specific food was introduced into the diets of people in the geographic area of the person you are studying. </span>
