We write DE = q+w, where DE is the internal energy change and q and w are heat and work, respectively.
(b)Under what conditions will the quantities q and w be negative numbers?
q is negative when heat flows from the system to the surroundings, and w is negative when the system does work on the surroundings.
As an aside: In applying the first law, do we need to measure the internal energy of a system? Explain.
The absolute internal energy of a system cannot be measured, at least in any practical sense. The internal energy encompasses the kinetic energy of all moving particles in the system, including subatomic particles, as well as the electrostatic potential energies between all these particles. We can measure the change in internal energy (DE) as the result of a chemical or physical change, but we cannot determine the absolute internal energy of either the initial or the final state. The first law allows us to calculate the change in internal energy during a transformation by calculating the heat and work exchanged between the system and its surroundings.
Answer:
B. oxygen and glucose
Explanation:
Oxygen for respiration and glucose for energy utilization
Answer: The answer is salt
Answer:
Permanent Magnets are always magnetic.
Temporary Magnets loose their magnetizing power after the source is removed. (outside a magnetic field)
Electromagnets are made by sending electric coil around an iron rod. (I.e. Nail, coil, and batteries can pick up paperclips)
