Question

The Body Mass Index (BMI) is given by [BMI = mass / (height 2] where the mass is
measured in kg and height is measured in m. If a man of weight 800 N, and height 71 inches,
what is his BMI (in kg/m2)? Given that 1 m = 3.3 feet, and 1 foot =12 inches.

a) 11.3
b) 25.5
c) 28.2
d) 27.7
e) 23

Answer 1

Answer on Question #41031, Physics, Mechanics

Question:

The Body Mass Index (BMI) is given by [BMI = mass / (height 2)] where the mass is measured in kg and height is measured in m. If a man of weight 800 N, and height 71 inches, what is his BMI (in kg/m²)? Given that 1 m = 3.3 feet, and 1 foot = 12 inches.

a) 11.3

b) 25.5

c) 28.2

d) 27.7

e) 23

Answer:

The Body Mass Index (BMI) is given by:

$$BMI = \frac{m}{h^2}$$

where $m$ is mass measured in kg, $h$ is height is measured in m.

Weight of the man equals:

$$P = mg$$

therefore mass equals:

$$m = \frac{P}{g} = \frac{800\,N}{9.81\,m/s^2} = 81.6\,kg$$

Height in meters equals:

$$h = \frac{71}{12 \cdot 3.3} = 1.79\,m$$

Therefore:

$$BMI = \frac{81.5}{1.79^2} = 25.5\,\frac{kg}{m^2}$$

Answer: b) 25.5