The amount of work performed by a system at consistent pressure is defined by the following equation:

where
p represents pressure

as the final volume

as the initial volume
Plugging the values given in this case into the formula gives us

Considering that

, the result for the work done becomes
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.
through the Doppler effect. The formula for apparent frequency is derived as F apparent = F real x (Vair ± Vobserver) / (Vair ± Vsource). In this scenario, should the observer move towards the source—place a positive sign in the numerator and a negative in the denominator. Since the observer approaches the wall, we apply the formula to derive the necessary speed.