A man weighs 162 pound. What is his mass in kg?
The correct answer and explanation is:
To convert the weight of the man from pounds to kilograms, you need to use the conversion factor where 1 pound is equal to approximately 0.453592 kilograms.
The formula to convert pounds to kilograms is: Mass (kg)=Weight (lbs)×0.453592\text{Mass (kg)} = \text{Weight (lbs)} \times 0.453592
Given the weight is 162 pounds, the calculation would be: Mass (kg)=162×0.453592=73.485 kg\text{Mass (kg)} = 162 \times 0.453592 = 73.485 \, \text{kg}
So, the man’s mass is approximately 73.49 kg.
Explanation:
The weight of an object or person is the force exerted by gravity on their mass. In the imperial system, weight is typically measured in pounds (lbs), while in the metric system, mass is measured in kilograms (kg). However, weight and mass are often confused because they are closely related. In physics, weight is the force, and mass is the measure of the amount of matter in an object.
The conversion factor between pounds and kilograms is based on the standard gravitational force. Since the force of gravity is constant, the relationship between weight and mass is predictable. By multiplying the number of pounds by the conversion factor (0.453592), you get the mass in kilograms. It is important to remember that weight changes with gravity, while mass remains constant regardless of location. This conversion is necessary for comparing the mass of objects in different systems of measurement.
This approach ensures that even if a person’s weight changes due to varying gravitational forces (for example, on different planets), their mass remains the same.