Which action can be explained by physics ?

Physics

2 answers:

LiRa [457]3 years ago

8 0

The pressure of blood exerted on the inner walls of the veins

Elis [28]3 years ago

3 0

Answer:

Option (d)

Explanation:

The pressure of blood exerted on the inner walls of the veins.

Pressure is defined a the force acting on the surface per unit area.

$Pressure = \frac{Force}{Area}$

The SI unit of pressure is Newton per square metre.

More be the force more be the pressure.

As due to the deposition of cholesterol on the walls of veins, the area of cross section of walls decreases which results the increase in pressure . It is very harmful for the heart, it may cause heart failure as heart do extra work to pump the blood.

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Sharks are generally negatively buoyant; the upward buoyant force is less than the weight force. This is one reason sharks tend

Tresset [83]

Answer:

8.67807 N

34.7123 N

Explanation:

m = Mass of shark = 92 kg

$\rho_{se}$ = Density of seawater = 1030 kg/m³

$\rho_{f}$ = Density of freshwater = 1000 kg/m³

$\rho_{sh}$ = Density of shark = 1040 kg/m³

g = Acceleration due to gravity = 9.81 m/s²

Net force on the fin is (seawater)

$F_n=mg-V_s\rho_{se}g\\\Rightarrow F_n=mg-\frac{m}{\rho_{sh}}\rho_{se}g\\\Rightarrow F_n=92\times 9.81-\frac{92}{1040}\times 1030\times 9.81\\\Rightarrow F_n=8.67807\ N$

The lift force required in seawater is 8.67807 N

Net force on the fin is (freshwater)

$F_n=mg-V_s\rho_{f}g\\\Rightarrow F_n=mg-\frac{m}{\rho_{sh}}\rho_{f}g\\\Rightarrow F_n=92\times 9.81-\frac{92}{1040}\times 1000\times 9.81\\\Rightarrow F_n=34.7123\ N$