# Newton's Laws of Motion - Physics 101 / AP Physics 1 Review - Dianna Cowern | Summary and Q&A

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September 22, 2020
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Physics Girl
Newton's Laws of Motion - Physics 101 / AP Physics 1 Review - Dianna Cowern

## TL;DR

This video lesson explores Newton's Laws of Motion, including inertia, force, mass, and acceleration, with real-life examples and practical applications.

## Key Insights

• 😣 Inertia is the property of objects to resist changes in their state of motion, either at rest or in motion.
• 💱 Forces cause changes in motion, whether by increasing or decreasing speed or changing direction.
• 👮‍♂️ Newton's second law, F = ma, is a fundamental equation in physics that relates force, mass, and acceleration.
• 👮 Newton's third law states that for every action, there is an equal and opposite reaction, showcasing the reciprocal nature of forces.
• ☠️ Gravity, as a force, follows Newton's laws of motion, with all objects falling at the same rate of acceleration near the Earth's surface.
• 💱 Forces can be balanced or unbalanced, resulting in either zero acceleration or changes in motion.
• 🥹 Tension is a force that can balance out other forces, as seen in situations where ropes provide support or hold objects in place.

## Transcript

(host) This is a terrifying trick. Check it out. The truck accelerates fast and pulls right out from underneath this skater-- this really talented guy from Braille Skateboarding-- pretty nuts. Hey, I'm Dianna Cowern. And welcome to Lesson 4 of Dianna's Intro Physics Class, also known as AP Physics 1 Review, also known as Physics by Dianna. Today's ... Read More

### Q: Why does the skater in the truck trick not accelerate with the truck?

The skater does not accelerate with the truck because there is very little friction acting on the skater from the skateboard wheels. As a result, the skater remains inert and does not move with the accelerating truck.

### Q: How does Newton's first law relate to objects in space?

Newton's first law states that objects in motion will continue moving unless acted upon by a force. In space, where there is no air resistance or friction, objects will continue moving in a straight line at a constant velocity unless influenced by external forces such as gravity.

### Q: How does Newton's second law explain the relationship between force, mass, and acceleration?

According to Newton's second law, force is directly proportional to both mass and acceleration. This means that the more mass an object has, the greater the force needed to accelerate it. Similarly, the greater the force applied to an object, the greater its acceleration.

### Q: What is tension, and how does it play a role in balancing forces?

Tension is a force transmitted through a rope, string, or similar object when it is pulled or stretched. In the example of the cow being lifted by a rope, the tension force in the rope balances out the force of gravity, resulting in an overall net force of zero and zero acceleration.

## Summary & Key Takeaways

• Newton's first law, or the law of inertia, states that objects at rest remain at rest and objects in motion remain in motion unless acted upon by a force.

• Newton's second law relates force, mass, and acceleration, stating that force equals mass times acceleration (F = ma).

• Newton's third law explains that for every action, there is an equal and opposite reaction, meaning that when one object exerts a force on another, the second object exerts an equal and opposite force back.