Use the equation of motion to answer the question.
x=x0+v0t+12at2
An object has a starting position of x = 2 m, a starting velocity of 4.5 m/s, and no acceleration. Which option shows the final position of the object after 2 s?
9 m
5.5 m
18 m
11 m
Calcium oxide and carbon dioxide combine to form calcium carbonate in the reversible reaction:
CaO + CO2 ⇌ CaCO3
When the reaction is at dynamic equilibrium, which statement must be true?
Calcium carbonate and calcium oxide are formed at the same rate.
The forward and reverse reactions have stopped.
The concentration of calcium carbonate is increasing.
The reaction has run out of carbon dioxide or calcium oxide.
Newton’s cradle is a contraption where metal balls hang from a frame. When one ball is pulled and released, the collision causes one ball on the opposite end to be released.
Which type of force can decrease the total momentum of this system?
strong nuclear force
magnetic force
gravitational force
electrostatic force
Which statement about the number of protons and neutrons in a nuclear change is correct?
The total charge before and after the change remains the same, but the total atomic mass is different.
The total atomic mass before and after the change remains the same, but the total charge is different.
The total number of neutrons and the total number of protons are the same before and after the change.
The number of protons and the number of neutrons can differ before and after the change, but the total number of those particles remains the same.
Hydrochloric acid and sodium hydroxide react to produce water and sodium chloride in an endothermic reaction. Which statement must be true of the reaction?
The total bond energy of water and sodium chloride is greater than the total bond energy of hydrochloric acid and sodium hydroxide.
The bond energy used to break the bonds in hydrochloric acid and sodium hydroxide is less than the energy released to form the bonds in water and sodium chloride.
More bond energy is absorbed on the reactants side than is released on the products side.
The energy of each bond in water and sodium chloride is greater than the energy of each bond in hydrochloric acid and sodium hydroxide.
To answer the question about the final position of the object after 2 seconds using the equation of motion x = x0 + v0t + 1/2at^2, we can substitute the given values into the equation and solve for x.
Given:
x0 = 2 m (starting position)
v0 = 4.5 m/s (starting velocity)
t = 2 s (time)
a = 0 m/s^2 (no acceleration)
Substituting these values into the equation:
x = 2 + (4.5)(2) + 1/2(0)(2^2)
x = 2 + 9 + 0
x = 11 m
Therefore, the final position of the object after 2 seconds is 11 m.
Moving on to the second question about the dynamic equilibrium in the reaction CaO + CO2 ⇌ CaCO3. At dynamic equilibrium, the rates of the forward and reverse reactions are equal, and there is no net change in the concentration of the reactants and products. So, the statement "Calcium carbonate and calcium oxide are formed at the same rate" must be true.
For the third question about Newton's cradle, the type of force that can decrease the total momentum of the system is the gravitational force. When one ball is released and swings upward, it loses momentum due to the gravitational force acting against its motion. This decrease in momentum is transferred through the system, causing the ball on the opposite end to be released.
Moving on to the fourth question about the number of protons and neutrons in a nuclear change, the correct statement is "The number of protons and the number of neutrons can differ before and after the change, but the total number of those particles remains the same." In a nuclear change, such as radioactive decay or nuclear fusion/fission, the number of protons and neutrons in the atomic nucleus can change, but the total number of protons and neutrons (the atomic mass) remains the same.
Lastly, for the question about the reaction between hydrochloric acid and sodium hydroxide, since the reaction is stated to be endothermic, more energy is absorbed on the reactants side than is released on the products side. Therefore, the statement "More bond energy is absorbed on the reactants side than is released on the products side" must be true.