If a person weighs 160 pounds, and the surface area of the bottom of both feet combined is 200 cm2. What is the pressure under the person’s feet (unit: N/m2)? What is the pressure if the person stands on only one foot (unit: N/m2)? [Hint: 1 kg = 2.2 lbs, 1 cm = 0.01 m, 1 cm2 = 0.0001 m2]
pressurebothfeet=W/area=160*1kg/2.2lbs /(.0001*200)
compute that.
To calculate the pressure under the person's feet, we need to use the formula:
Pressure = Force/Area
Let's start by converting the weight from pounds to kilograms:
Weight in kg = 160 pounds / 2.2 pounds/kg = 72.73 kg (approximately)
Next, we need to convert the area from cm2 to m2:
Surface area in m2 = 200 cm2 * 0.0001 m2/cm2 = 0.02 m2
Now we can calculate the pressure when the person stands on both feet:
Pressure = Weight in N / Surface area
First, let's convert the weight from kilograms to Newtons:
Weight in N = Weight in kg * 9.8 m/s2 (acceleration due to gravity)
Weight in N = 72.73 kg * 9.8 m/s2 ≈ 713.20 N
Now we can calculate the pressure:
Pressure = 713.20 N / 0.02 m2 ≈ 35,660 N/m2
Therefore, the pressure under the person's feet, when standing on both feet, is approximately 35,660 N/m2.
To calculate the pressure when the person stands on only one foot, we need to divide the weight and surface area by 2:
Weight in N (one foot) = 713.20 N / 2 ≈ 356.60 N
Surface area in m2 (one foot) = 0.02 m2 / 2 = 0.01 m2
Now we can calculate the pressure:
Pressure (one foot) = 356.60 N / 0.01 m2 = 35,660 N/m2
Therefore, the pressure under the person's foot, when standing on one foot, is also approximately 35,660 N/m2.