All the weight of the wooden board rests solely on the support situated at the center of the rod, while the other support positioned at one end experiences no reaction force, resulting in a 0 reaction force.
Thus, the reaction force at the central support corresponds to the weight of the board, whereas the end support has 0 reaction force.
The object's density is 8000 kg/m^3. The object's weight in air is 7.84 N while it measures 6.86 N when submerged in water, where the density of water is 1000 kg/m^3. According to Archimedes' principle, an immersed object experiences an upward buoyant force equivalent to its loss of weight in the fluid. By calculating the weight difference (7.84 - 6.86 = 0.98 N) and employing the standard equations relating density and volume, we find that 10^-4 m^3 corresponds to a density of 8000 kg/m^3.
The astronaut's speed is described in the sentence. The astronaut moves at a rate of 10 meters each minute. To clarify: speed is defined as distance divided by time and is characterized solely by its magnitude, not its direction. Hence, the 10 meters per minute reflects this. We lack information about the astronaut's directional movement. In contrast to speed, velocity incorporates direction as well; for instance, a velocity of 10m/s due west provides a directional context. Consequently, without specified direction, the value indicated is merely speed.
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.
