Potential Energy 2.1.4

Potential Energy
Lesson 2.1.4

• describe how potential energy can become kinetic energy

• calculate the potential energy of an object

Draw

Let's Review!

KE=1/2mv²

^m=mass=kg

^{v=velocity=m/s}

What is the kinetic energy of a 9kg fish traveling 3m/s underwater?

​ https://www.cnn.com/2024/09/09/health/energy-drinks-caffeine-dangers-wellness/index.htmlwww.cnn.com

The Hidden Danger of energy drinks. A Doctor Explains 9/9/2024

What are the potential dangers of consuming energy drinks?

CNN: Can drinking a lot of energy drinks be dangerous?

Wen: Yes, especially because of excessive caffeine consumption.

A large amount of caffeine can cause rapid heartbeat. People can become jittery and
anxious. They may have trouble sleeping, which paradoxically causes more fatigue over
time. Those who consume energy drinks thinking that they replenish
electrolytes and fluids may become dehydrated, especially as caffeine is a
diuretic that promotes fluid loss. A very large amount of caffeine consumption
can lead to caffeine intoxication. This is uncommon but can be dangerous, even
life-threatening, especially when the heart rhythm is disrupted. Individuals could
suffer cardiac arrest as well as other severe symptoms such as brain swelling
and kidney failure.

​What is the meaning of the word potential in the question above?

Potential Energy: the amount of energy that is stored in an object.

How does the peregrine falcon relates to potential energy?

Watch the Edio video page 2

Potential energy comes in many forms, including:

• energy of position;

• chemical energy; and

• batteries.

Energy of Position

The energy of position is a common type of potential energy. Any object located above the ground has energy from its position. Consider the plants on these shelves.

The plants are not moving, so they have no kinetic energy. However, the plants have the potential to fall off the shelf toward the ground. The plants have potential energy because gravity pulls them toward Earth. This potential energy comes from the position of the plants above the ground.

​Chemical Energy

Recall that chemical energy is energy stored within molecules. Many molecules, or groups of atoms, contain energy stored in the bonds between the atoms. Rearranging those atoms can release the chemical energy to convert it to kinetic energy.

Chemical energy is commonly found in:

• food

• fuel

• batteries

Your body uses the chemical energy in the food you eat to move, grow, and think. You release chemical energy in fuels such as gasoline and coal when you burn them.

​burning coal

​Batteries

A battery is a device that converts chemical energy into electrical energy. Substances inside the battery contain chemical energy. Electrical devices use that chemical energy to produce electricity and do work.

Many devices you use daily contain batteries. These devices include:

• smart phones

• vehicles

• laptops

Batteries contain potential energy because they store energy to use at a later time.

Match

Match each scenario to the type of potential energy it describes.

• battery

• an apple

• energy of position

plugging in a cell phone

chemical energy

a child at the top of a sliding board

• plugging in a cell phone

• chemical energy

• a child at the top of a sliding board

Poll

When an object has energy from its position, the potential energy can become kinetic energy if the object falls. Potential energy is stored energy, or energy that has the potential to become work.

• TRUE

• FALSE

• I HAVE NO IDEA

Edio lesson page 3 Video Part II

Now, watch Coyote skydive to try to race a peregrine falcon to the ground to catch his prey. As you view the video, consider when the skydiver has kinetic energy and when he has potential energy.

Drag and Drop

Examples of potential energy: ​

Placeholder

​

Placeholder

Drag these tiles and drop them in the correct blank above

sitting in an airplane

standing on a diving board

skydiving

hitting a baseball

On Earth, the value for g is always 9.8 m/s²

• PE represents potential energy

• m represents mass

• g represents gravity from Earth

• h represents height above the ground

​PE= mgh

Potential Energy Problems

​The value of g represents the strength of the pull of Earth's gravity on an object.

Screenshot this:

​1. diagram 2.formula 3.variables 4.substitution 5. solution

​PE=mgh

​PE=?
m=0.9 kg
g=9.8/s²
h=200 m

​PE=mgh
PE=0.9 ⋅ 9.8 ⋅ 200

​PE= Joules

​A peregrine falcon has a mass of about 0.9 kg. What is the potential energy of a peregrine falcon soaring above Earth's surface at 200m. ?

Sample Problem#2

What is the potential energy of a skydiver in a plane 500 m. above Earth's surface?

Page 6 in Edio~Watch the Video

Draw

What is the potential energy of a 3 kg. cat sitting on top of a 2 m. wall?

PE=mgh

g=9.8 m/s²

Draw

What is the potential energy of a 0.5 kg book sitting on top of a 1.5 m. shelf?

PE=mgh

g=9.8 m/s²

Poll

How do you feel about finding potential energy using formulas?