Potential Energy — Reading Comprehension

Potential energy is a form of stored energy that objects have because of their position or condition. In science, understanding how and why objects can store energy helps us explain many phenomena, from the movement of a roller coaster to the tension in a stretched rubber band. Unlike kinetic energy, which is the energy of motion, potential energy depends on where an object is located or how it is shaped. Scientists use precise measurements and careful observations to quantify how much energy is stored, and these calculations are essential for engineering, safety, and technology.

Gravitational Potential Energy: Height Matters

Gravitational potential energy is the energy stored in an object because of its vertical position, or height, above the Earth. The higher an object is, the more gravitational potential energy it has. This is because gravity, the force that pulls objects toward Earth, can do more work on objects when they are higher up. For example, when a book rests on a shelf, it has more gravitational potential energy than the same book lying on the floor. If the book falls, its potential energy is converted into kinetic energy as it speeds toward the ground. Scientists use the formula: Potential Energy = mass × gravity × height (PE = mgh), where mass is measured in kilograms, gravity is about 9.8 m/s², and height is in meters. This formula helps engineers design safe roller coasters and calculate how much energy is needed to lift objects.

Elastic Potential Energy: Stretched and Compressed Objects

Elastic potential energy is stored when materials like rubber, springs, or bows are stretched or compressed. When you pull back a bowstring or stretch a rubber band, you are doing work on the object, and that work is stored as elastic potential energy. When the object is released, the stored energy rapidly converts into kinetic energy, causing motion. For example, a drawn bow stores energy that launches an arrow, and a compressed spring can push objects apart. The amount of elastic potential energy depends on how much the object is stretched or compressed and the properties of the material. Engineers use this principle to design devices like trampolines, car suspensions, and even toys.

Interactions and Everyday Applications

Potential energy is not limited to simple objects. Large systems, such as a dam holding back water, also demonstrate this concept. The water behind a dam has significant gravitational potential energy due to its height. When released, the water flows downward, its energy harnessed to turn turbines and generate electricity. Similarly, roller coasters are designed to maximize potential energy at the highest point, which is then transformed into motion as the cars descend. By understanding how energy is stored and converted, scientists and engineers can create safer structures, generate power, and develop innovative technologies.

Potential energy is a key idea in physical science and is connected to the broader principle of energy conservation: energy cannot be created or destroyed, only transformed. Exploring how potential energy works helps us predict natural events, design useful devices, and appreciate the hidden energy all around us.

Interesting Fact: The world’s largest hydroelectric dam, the Three Gorges Dam in China, stores enough potential energy in its reservoir to generate over 22,000 megawatts of electricity!

What is potential energy?

Which of the following is an example of gravitational potential energy?

According to the passage, what happens when a stretched rubber band is released?

What does the formula PE = mgh help scientists and engineers calculate?

In the context of the passage, what does 'energy conservation' mean?

What is the main difference between kinetic and potential energy?

Why does a roller coaster car at the top of a hill have a lot of potential energy?

Which statement about the Three Gorges Dam is TRUE according to the passage?

True or False: Elastic potential energy only exists in objects that are moving.

True or False: Energy can be created or destroyed, according to the passage.