Any help would be apreciated!

Which of the following is a way to improve the efficiency of a heat engine?
increase Qh
reduce Qh
reduce Wnet
increase Qc
A

What are the energies associated with atomic motion called?
kinetic energy
potential energy
bond energy
internal energy
D

A 0.10 kg piece of copper at an initial temperature of 95°C is dropped into 0.20 kg of water contained in a 0.28 kg aluminum calorimeter. The water and calorimeter are initially at 15°C. What is the final temperature of the system when it reaches equilibrium?
mw = 0.20kg
cp,w = 4186J/kg°C
mAl = 0.28kg
cp,Al = 899J/kg°C
Tw = TAl = 15°C
mCu = 0.10kg
cp,Cu = 387J/kg°C
TCu = 95°C

18

Thank you!

To improve the efficiency of a heat engine, the most effective way is to reduce Qh, which represents the amount of heat the engine absorbs from the hot reservoir. By reducing the heat input, less energy is wasted and more of it can be converted into useful work. Hence, the answer is B - reduce Qh.

The energies associated with atomic motion are called internal energy. It includes both kinetic energy, which is the energy due to the motion of atoms, and potential energy, which is the energy associated with the interactions between atoms. Therefore, the answer is D - internal energy.

To find the final temperature of the system when it reaches equilibrium, you can utilize the principle of conservation of energy. The heat lost by the copper and gained by the water and calorimeter can be equated since they reach thermal equilibrium.

Firstly, calculate the heat lost by the copper using the formula:
Qcopper = mcopper * cp,copper * (TCu - Tf)

Next, calculate the heat gained by the water using:
Qwater = mw * cp,water * (Tf - Tw)

And finally, calculate the heat gained by the calorimeter (since it is made of aluminum) using:
Qcalorimeter = mcalorimeter * cp,aluminum * (Tf - Tw)

Since the heat lost by the copper is equal to the total heat gained by the water and calorimeter, you can set up an equation and solve for Tf:

mcopper * cp,copper * (TCu - Tf) = mw * cp,water * (Tf - Tw) + mcalorimeter * cp,aluminum * (Tf - Tw)

Plugging in the given values:
0.10kg * 387J/kg°C * (95°C - Tf) = 0.20kg * 4186J/kg°C * (Tf - 15°C) + 0.28kg * 899J/kg°C * (Tf - 15°C)

Simplify and solve for Tf to find the final temperature of the system when it reaches equilibrium. In this case, the final temperature is 18°C.