g = 9.8 m/s²
A person weighing 160 lbs has a mass of _ kg and a weight of _ Newton’s I Kg = 2.205 lbs
g = 9.8 m/s²
The Correct Answer and Explanation is:
Answer:
A person weighing 160 lbs has:
- Mass: Mass (kg)=160 lbs2.205 lbs/kg≈72.56 kg\text{Mass (kg)} = \frac{160 \text{ lbs}}{2.205 \text{ lbs/kg}} \approx 72.56 \text{ kg}
- Weight in Newtons: Weight (N)=mass×g=72.56 kg×9.8 m/s2≈710.09 N\text{Weight (N)} = \text{mass} \times g = 72.56 \text{ kg} \times 9.8 \text{ m/s}^2 \approx 710.09 \text{ N}
Explanation
In physics, mass and weight are two related but distinct concepts. Mass is a measure of the amount of matter in an object and is expressed in kilograms (kg) in the SI system. It is an intrinsic property and does not change regardless of location. Weight, on the other hand, is a force that results from the gravitational pull on an object’s mass. It depends on both the mass of the object and the gravitational acceleration acting on it, and it’s measured in Newtons (N).
To convert from pounds (lbs) to kilograms (kg), we use the conversion factor: 1 kg=2.205 lbs1 \text{ kg} = 2.205 \text{ lbs}
This means that a person who weighs 160 lbs has a mass of: 1602.205≈72.56 kg\frac{160}{2.205} \approx 72.56 \text{ kg}
Next, to find the weight in Newtons, we multiply the mass by the acceleration due to gravity on Earth, which is approximately 9.8 m/s². This gives: Weight (N)=72.56×9.8≈710.09 N\text{Weight (N)} = 72.56 \times 9.8 \approx 710.09 \text{ N}
It’s important to note that while the term “weight” is often used colloquially to mean mass (e.g., “I weigh 160 lbs”), scientifically speaking, weight is a force, not a mass. Thus, your “weight” in Newtons would change on another planet due to different gravitational strength, but your mass in kilograms remains the same.
Understanding the difference is crucial in science and engineering, especially in fields like physics, aerospace, and biomechanics, where precise measurements matter.
