Response:
(a) 
(b) 
Clarification:
Greetings.
(a) In this case, since the starting volume is 18.5 dm³ and the ending volume is 21 dm³ (18.5 +2.5), we can calculate the work at constant pressure as shown below:

This value is negative as it expands against the given pressure.
(b) Furthermore, if the process is conducted reversibly, the pressure might change, hence, we need to calculate the work using:

The moles are calculated based on the provided mass of argon:

Consequently, the work amounts to:

Best regards.
Initially, the magnetic domains within the nail were oriented in various directions before coming into contact with the bar magnet. Upon Taylor touching the nail to the bar magnet, the magnetic fields of those domains became aligned, thus transforming the nail into a temporary magnet.
Infiltration
Explanation:
The feature of the hydrologic cycle most impacted by impervious surfaces like concrete and asphalt is infiltration.
- Infiltration is crucial within the hydrologic cycle.
- Concrete and similar materials hinder water absorption into the ground.
- This adversely affects existing groundwater systems.
- A rise in surface runoff can occur, leading to potential flooding.
- Infiltration plays a pivotal role in the water cycle.
- It supplies water to plant roots and replenishes groundwater reserves.
- Impervious surfaces disrupt this natural process.
learn more:
Biogeochemical cycle
Answer:

Explanation:
The overall energy expenditure of the salmon, which corresponds to its swimming upstream effort,
, is linked to its specific mechanical power.
calculated per unit mass can be derived from the following equation:

As a result, the total energy utilized during the 22-day journey is 7.603 MJ
Response: 800N
Clarification:
Provided data:
Ball mass = 0.8kg
Contact duration = 0.05 seconds
Final and initial speed = 25m/s
The average force exerted by the ball on the wall can be calculated using the following relationship:
Force (F) = mass (m) * average acceleration (a)
a= (initial velocity (u) + final velocity (v))/t
m = 0.8kg
u = v = 25m/s
t = contact time of the ball = 0.05s
Thus,
a = (25 + 25) ÷ 0.05 = 1000m/s^2
Hence,
The average force magnitude (F)
F=ma
m = ball mass = 0.8
a = 1000m/s^2
F = 0.8 * 1000
F = 800N