Physics 2002 JAMB Past Questions - Question 8: The hydrostatic blood pressure difference between the head and the feet of a boy standing straight is 1.65 x 104 Nm-2. Find the height of the boy.[ Density of blood = 1.1 x 103 kgm-3, g = 10ms-2]

Correct Answer

D

Explanation

To find the height of the boy, we can use the hydrostatic pressure formula and the density of blood. The hydrostatic pressure difference between the head and feet is due to the difference in the height of the blood column. The formula for hydrostatic pressure is:

P = ρ * g * h

Where:
P = pressure (in pascals, Pa)
ρ = density of the fluid (in kilograms per cubic meter, kg/m³)
g = acceleration due to gravity (approximately 9.81 m/s² on the surface of the Earth)
h = height (in meters, m)

In this case, the pressure difference between the head and feet is 1.65 x 10^4 N/m² (Pa), and we can assume the density of blood is approximately 1,060 kg/m³. We'll use the value of 9.81 m/s² for the acceleration due to gravity.

P = 1.65 x 10^4 Pa
ρ = 1,060 kg/m³
g = 9.81 m/s²

Now, we can solve for h (the height of the boy):

1.65 x 10^4 Pa = 1,060 kg/m³ * 9.81 m/s² * h

Now, solve for h:

h = (1.65 x 10^4 Pa) / (1,060 kg/m³ * 9.81 m/s²)

h ≈ 1.61 meters

So, the height of the boy is approximately 1.61 meters.