GCSE Physics Revision "Elastic Potential Energy"

Summary

This video explains the concept of elastic potential energy and how it is stored in a stretched spring. Viewers learn that applying a force to stretch a spring stores energy, called elastic potential energy. The video discusses how extension is directly proportional to the applied force until the spring reaches its limit of proportionality. It introduces the formula to calculate elastic potential energy, emphasizing the importance of units and how to convert them. A sample problem is provided, showing step-by-step calculations to reinforce understanding.

Takeaways

• 📚 Elastic potential energy is the energy stored in a stretched spring.
• 🔧 When we apply a force to stretch a spring, we're doing work and transferring energy into the spring.
• 🧸 Examples of items that use elastic potential energy include windup toys and clocks.
• 📐 The extension of a spring is directly proportional to the force applied, as shown by a straight-line graph.
• ⚠️ If the spring is stretched beyond its limit of proportionality, it will not return to its original length.
• 🔢 The formula to calculate elastic potential energy is 0.5 multiplied by the spring constant and the square of the extension.
• 📏 The extension must be measured in meters, so any other unit (like centimeters) must be converted.
• 🔨 The spring constant is specific to each spring and is given in Newtons per meter (N/m).
• 📝 In an example problem, a spring with an extension of 20 cm and a spring constant of 100 N/m stores 2 joules of elastic potential energy.
• 📖 Practice problems and further resources can be found in the provided revision workbook.

Q & A

What is elastic potential energy?

Elastic potential energy is the energy stored in a stretched or compressed spring.

How is elastic potential energy related to stretching a spring?

When a spring is stretched by applying a force, energy is stored in the spring in the form of elastic potential energy.

What does the term 'doing work' mean in the context of stretching a spring?

In this context, 'doing work' means applying a force to change the length of the spring, thereby transferring energy into the spring.

What happens if you apply too much force to a spring?

If too much force is applied, the spring will exceed its limit of proportionality and will not return to its original length after the force is removed.

What does it mean for a spring to reach its limit of proportionality?

The limit of proportionality is the point beyond which the extension of the spring is no longer directly proportional to the applied force.

What is the equation for calculating elastic potential energy?

The equation is: Elastic Potential Energy = 0.5 × Spring Constant × Extension².

What units must the extension be in when calculating elastic potential energy?

The extension must be in meters (m) when calculating elastic potential energy.

What is the spring constant, and how does it affect elastic potential energy?

The spring constant is a measure of the stiffness of a spring. A higher spring constant means the spring is stiffer, and it requires more force to stretch.

How do you convert an extension from centimeters to meters?

To convert from centimeters to meters, divide the value in centimeters by 100.

If a spring has an extension of 20 cm and a spring constant of 100 N/m, how much elastic potential energy is stored in the spring?

First, convert 20 cm to meters (0.2 m). Then, using the equation: Elastic Potential Energy = 0.5 × 100 N/m × (0.2 m)² = 2 Joules.