I have a few questions that I don't understand and would like to get checked, please?

5.If energy is conserved and momentum is conserved, would they both have to be conserved simultaneously in some interaction?

My answer: No because each engergy and momemtum is being conserverd.

9. A 60 kg skydiver moving at terminal speed falls 50m in 1 s. What power is the skydiver expending on the air?

My answer: p=work/time
p=50m/1s=50 Watt

12.Where, exactly, does the energy stored in oil come from? How can we get "work" from oil? In your discussion, try to use the words work, energy, heat, power, and conservation in their correct physical sense.

-I don't understand this question.

The answer to 5. is yes, but some of the energy may be heat and not show up in equations of motion. Only elastic collision conserve (kinetic + potential) energy.

9. Your equation is wrong. You cannot divide distance by time to get power. At terminal speed,
(powerloss) = weight x velocity.
The average power for the one second is M g/(1 sec)

12. The energy from oil starts with chemical energy in the molecules that gets converted to heat in an engine (by reacting with oxygen), and then converted to mechanical energy when a piston is pushed by hot combustion products.

Let's check the answers to the questions you provided step by step:

5. If energy is conserved and momentum is conserved, would they both have to be conserved simultaneously in some interaction?

Your answer: "No because each energy and momentum is being conserved."

Explanation: Actually, both energy and momentum can be conserved simultaneously in an interaction. In physics, the principle of conservation of energy states that the total energy of a closed system remains constant over time. Similarly, momentum is conserved in a closed system where no external forces act upon it. In some interactions, both energy and momentum can be conserved. It is important to note that the conservation of momentum does not depend on the conservation of energy, and vice versa. They are separate principles that can apply independently or simultaneously, depending on the specific situation.

9. A 60 kg skydiver moving at terminal speed falls 50m in 1 s. What power is the skydiver expending on the air?

Your answer: "p=work/time p=50m/1s=50 Watt"

Explanation: Your calculation is not correct. The power expended by the skydiver can be calculated using the equation P = W/t, where P is power, W is work, and t is time. In this case, the work done by the skydiver is equal to the product of force and displacement (W = F * d). Since the skydiver is moving at a constant speed, the net force acting on them is zero, which means no work is being done. Therefore, the power expended by the skydiver on the air is zero.

12. Where, exactly, does the energy stored in oil come from? How can we get "work" from oil? In your discussion, try to use the words work, energy, heat, power, and conservation in their correct physical sense.

Your response: "I don't understand this question."

Explanation: The question is asking about the origin of the energy stored in oil and how we can extract useful work from it. In a simplified sense, the energy stored in oil comes from ancient sunlight. Millions of years ago, plants and other organisms captured the sun's energy through photosynthesis and stored it as chemical energy in their biomass. Over time, these organic materials transformed into oil through processes such as compression and decomposition.

To obtain useful work from oil, we typically burn it, which releases heat energy. This heat energy can be converted into other forms of energy, such as mechanical energy, electrical energy, or even light energy. For example, oil can be burned in an engine to generate mechanical energy that moves a vehicle.

In this process, there are conversions between different forms of energy (chemical energy in oil to heat energy) and the transfer of energy (heat energy to mechanical energy). Power, which is the rate at which work is done or energy is transferred, plays a role in these conversions and transfers.

It is important to note that the principle of conservation of energy applies here. Energy is neither created nor destroyed; it is only converted from one form to another. In the case of burning oil, the chemical potential energy stored in the oil is converted into other forms of energy, such as heat and mechanical energy. This conservation principle is a fundamental concept in physics.