Terminal Velocity and Air Resistance

Next Generation Science

11 May 202302:28

Summary

TLDRThis video explains how objects or people falling from a great height are affected by gravity and air resistance. Initially, they accelerate towards the ground until air resistance balances with gravity, reaching terminal velocity. For humans, terminal velocity can be dangerously fast, but parachutes increase air resistance, slowing the descent and allowing for a safe landing. The video encourages viewers to design their own parachute and experiment with timing the fall of small objects. Additional worksheets are available for download on the NG Science website.

Takeaways

🌍 Objects or people falling from great heights are pulled towards the Earth by gravity.
🚀 As an object falls, it accelerates, moving faster towards the ground.
🌬️ Air resistance, also known as drag force, pushes against the object, slowing it down.
⚖️ Terminal velocity occurs when the drag force equals the force of gravity, stopping further acceleration.
📏 Terminal velocity varies based on an object's shape, size, and mass.
🧑‍🚀 For a human, terminal velocity while falling through the air is around 120 miles per hour (193 km/h).
🪂 A parachute increases air resistance by creating a larger surface area, slowing the descent.
🛬 The parachute enables a safe landing by significantly reducing the speed of descent.
📝 The video encourages experimenting with designing parachutes for small objects to observe the slowing effect.
🎓 Worksheets related to this video are available for download on NG Science's website.

Q & A

What causes an object or person to fall towards the Earth?
-An object or person falls towards the Earth due to the force of gravity.
What happens to an object's speed as it falls?
-As an object falls, it accelerates, meaning it moves faster and faster towards the ground.
What role does air resistance play during a fall?
-Air resistance, or drag force, pushes against the falling object or person, slowing them down.
What is terminal velocity and how is it reached?
-Terminal velocity is the point at which the air resistance equals the force of gravity, causing the object or person to stop accelerating.
How does terminal velocity differ for different objects?
-Terminal velocity can vary depending on the shape, size, and mass of the object.
What is the approximate terminal velocity for a human falling through the air?
-The terminal velocity for a human falling through the air is around 120 miles per hour or about 193 kilometers per hour.
Why is terminal velocity too fast for a human to safely land on the ground?
-At terminal velocity, a human is falling too fast to safely land because the speed is too high for a safe impact.
How does a parachute help in a fall?
-A parachute increases air resistance by creating a larger surface area for the air to push against, slowing the descent and allowing for a safe landing.
When does a skydiver deploy their parachute during a fall?
-A skydiver deploys their parachute after reaching terminal velocity, to slow down their descent.
What experiment is suggested at the end of the script?
-The script suggests designing and making your own parachute to slow the fall of small objects, using a stopwatch to time the object's fall.

Outlines

00:00

🌍 Understanding Gravity and Terminal Velocity

When an object or person falls from a great height, they are pulled toward Earth due to gravity. As they descend, they accelerate, increasing in speed. However, air resistance, also known as drag force, works against them, slowing down the fall. Eventually, the drag force equals the force of gravity, causing the object or person to stop accelerating. This balance is called terminal velocity, which varies depending on the shape, size, and mass of the falling object. For a human falling through the air, terminal velocity is about 120 miles per hour or 193 kilometers per hour, which is too fast for a safe landing. To address this, parachutes are used to increase air resistance, slowing down the fall and enabling a safe descent.

🪂 Skydiving and Parachutes: How They Work

Skydivers experience a similar process. When they jump from a plane, gravity causes them to accelerate initially. As they fall, air resistance increases until it balances with gravity, and they reach terminal velocity. At this point, the skydiver deploys a parachute, which significantly increases air resistance, slowing their descent and allowing them to land safely.

🛠 Design Your Own Parachute Experiment

Viewers are encouraged to design and make their own parachutes to test how they can slow the fall of small objects. A stopwatch can be used to time the fall and measure the effectiveness of the parachute design.

📚 Additional Resources and Subscription

At the end of the video, viewers are informed about available worksheets that can be downloaded by creating a free account on NG Science's website. They are also encouraged to subscribe to the NG Science YouTube channel to stay updated on future videos.

Mindmap

Keywords

💡Gravity

Gravity is the natural force that pulls objects towards the center of the Earth. In the video, gravity is responsible for pulling the skydiver or object towards the ground when they fall. It plays a key role in the concept of terminal velocity and is the reason why objects accelerate as they fall.

💡Acceleration

Acceleration refers to the increase in speed as an object falls due to the force of gravity. The video explains how, when a skydiver or object falls from a height, they move faster and faster toward the ground until they reach a certain speed known as terminal velocity.

💡Air resistance

Air resistance, also known as drag force, is the force that pushes against a falling object, slowing it down. The video explains how air resistance opposes gravity, and eventually, the two forces balance out when the object reaches terminal velocity.

💡Terminal velocity

Terminal velocity is the constant speed that a falling object reaches when the force of gravity is balanced by air resistance. In the video, it is explained that once a person or object stops accelerating, they continue to fall at terminal velocity, which for a human is about 120 miles per hour.

💡Parachute

A parachute is a device that increases air resistance, slowing down the descent of a falling person or object. The video describes how the parachute creates a larger surface area, which allows air to push against it and reduce the speed at which the person or object falls.

💡Drag force

Drag force is another term for air resistance, and it refers to the force that opposes an object's motion through the air. The video mentions that the drag force becomes equal to the force of gravity at terminal velocity, stopping further acceleration.

💡Mass

Mass is the amount of matter in an object, which affects how gravity pulls on it. In the video, it is mentioned that the mass of an object, along with its shape and size, determines its terminal velocity and how fast it falls.

💡Surface area

Surface area refers to the total area of the exposed surface of an object. The video explains that parachutes work by increasing surface area, which in turn increases air resistance and slows down the falling object or person.

💡Descent

Descent refers to the downward movement of an object or person as they fall. The video explains that a parachute slows the descent of a skydiver, allowing them to land safely on the ground instead of falling at terminal velocity.

💡Skydiver

A skydiver is a person who jumps from an airplane and free-falls through the air before using a parachute to slow their descent. The video uses a skydiver as an example to explain how gravity, air resistance, and terminal velocity work in real-life scenarios.

Highlights

Objects or people falling from a great height are pulled towards Earth by gravity.

As an object or person falls, they accelerate, meaning they move faster towards the ground.

Air resistance, or drag force, pushes against falling objects, slowing them down.

When drag force equals the force of gravity, the object stops accelerating, a condition called terminal velocity.

Terminal velocity varies for different objects based on their shape, size, and mass.

For a human, terminal velocity is about 120 miles per hour or 193 kilometers per hour.

A speed of 120 miles per hour is too fast for a person to safely reach the ground.

Parachutes increase air resistance by providing a larger surface area, which slows the object's descent.

A parachute allows a person or object to land safely by reducing the fall speed.

Skydivers accelerate when they initially jump due to gravity.

Air resistance gradually increases during a skydive until it balances with gravity.

When a skydiver reaches terminal velocity, they deploy their parachute to slow down.

The parachute slows the descent, allowing the skydiver to land safely.

The video encourages designing and making parachutes to slow the fall of small objects.

Using a stopwatch to time the fall of small objects can help test parachute designs.