Examples of Applied Forces

📚 Quick Study Guide

🔍
• Applied Force: A force exerted on an object by a person or another object. It's what happens when you push, pull, kick, or throw something.
🍎
• Newton's First Law: An object at rest stays at rest, and an object in motion stays in motion with the same speed and in the same direction unless acted upon by a force. This force is often an applied force.
🏋️‍♀️
• Examples: Pushing a shopping cart, kicking a ball, lifting a book, pulling a rope, or even wind pushing against a sail are all examples of applied forces.
💡
• Formula: While there isn't a single formula *just* for applied force, it's often a component of force calculations using Newton's Second Law: $F = ma$, where $F$ is force, $m$ is mass, and $a$ is acceleration.
💪
• Friction: Keep in mind that applied forces often work against friction. You have to apply *more* force than the frictional force to get something moving.

✍️ Practice Quiz

1. Which of the following is the BEST example of an applied force?
   1. A leaf falling from a tree.
   2. A magnet attracting a nail.
   3. A person pushing a box across the floor.
   4. The Earth orbiting the Sun.
2. According to Newton's First Law, what happens to an object in motion if no applied force acts upon it?
   1. It immediately stops.
   2. It speeds up.
   3. It slows down.
   4. It continues moving at a constant velocity.
3. What force must generally be overcome by an applied force to start an object moving on a surface?
   1. Gravity
   2. Air resistance
   3. Friction
   4. Inertia
4. In the equation $F = ma$, what does 'F' represent?
   1. Mass
   2. Acceleration
   3. Force
   4. Velocity
5. Which of these scenarios does NOT primarily involve an applied force?
   1. A rocket launching into space.
   2. A car braking suddenly.
   3. A ball rolling down a hill.
   4. A weightlifter lifting a barbell.
6. If two people are pushing a box with forces of 50N each in the same direction, what is the net applied force?
   1. 25N
   2. 50N
   3. 75N
   4. 100N
7. A student is pulling a wagon with a force of 20N. However, friction is acting with a force of 5N in the opposite direction. What is the net force on the wagon?
   1. 5N
   2. 10N
   3. 15N
   4. 25N