Solved Examples: Calculating Weight using Fg = mg

📚 Quick Study Guide

• 🌍 Weight is the force exerted on an object due to gravity.
• 🔢 The formula for calculating weight ($F_g$) is: $F_g = mg$, where $m$ is mass and $g$ is the acceleration due to gravity.
• 🛰️ On Earth, $g$ is approximately $9.8 m/s^2$.
• ⚖️ Weight is measured in Newtons (N).
• 💡 Mass is a measure of how much matter an object contains, while weight is the force of gravity acting on that mass.

Practice Quiz

1. A book has a mass of 2 kg. What is its weight on Earth?
   1. 4.9 N
   2. 9.8 N
   3. 19.6 N
   4. 29.4 N
2. An astronaut has a mass of 70 kg. What is their weight on Earth where $g = 9.8 m/s^2$?
   1. 686 N
   2. 70 N
   3. 700 N
   4. 7 N
3. A cat weighs 49 N on Earth. What is its mass?
   1. 4.9 kg
   2. 5 kg
   3. 9.8 kg
   4. 49 kg
4. What happens to an object's weight if the gravitational acceleration ($g$) doubles, assuming the mass remains constant?
   1. Weight halves.
   2. Weight remains the same.
   3. Weight doubles.
   4. Weight quadruples.
5. A block of wood has a mass of 5 kg. If $g = 10 m/s^2$, what is the weight of the wood?
   1. 5 N
   2. 10 N
   3. 50 N
   4. 15 N
6. A stone weighs 98 N on Earth. What is its mass, assuming $g=9.8 m/s^2$?
   1. 1 kg
   2. 5 kg
   3. 10 kg
   4. 20 kg
7. A feather has a mass of 0.01 kg. What is its weight on Earth, given $g = 9.8 m/s^2$?
   1. 0.0098 N
   2. 0.098 N
   3. 0.98 N
   4. 9.8 N