Question

Complete the sentence by filling in the blanks. As an object falls from a table to the floor, it loses its stored ) energy and gains energy as it begins to speed up. When the object hits the ground, it loses its energy of motion, which is converted into energy.

Short answer

As an object falls from a table to the floor, it loses its stored \(gravitational\ potential\ energy\) and gains \(kinetic\ energy\) as it begins to speed up. When the object hits the ground, it loses its energy of motion, which is converted into \(other\ forms\ of\ energy\).

Step-by-step solution

Fill in the first blank

The first blank refers to the type of stored energy an object has when it is held above the ground. This is known as potential energy, specifically gravitational potential energy. So, we can fill in the first blank with "gravitational potential energy."

Fill in the second blank

The second blank refers to the energy an object gains while in motion, as it falls from a height. This type of energy is called kinetic energy. Thus, we can fill in the second blank with "kinetic energy."

Fill in the third blank

The third blank refers to the type of energy the object's energy of motion is converted into when it hits the ground. When the object hits the ground, it loses its kinetic energy, and this energy is converted into another form, such as sound energy, heat energy, or the energy transferred to the surrounding environment. In this case, we can be general and fill in the third blank with "other forms of energy." Completed Sentence: As an object falls from a table to the floor, it loses its stored gravitational potential energy and gains kinetic energy as it begins to speed up. When the object hits the ground, it loses its energy of motion, which is converted into other forms of energy.

Key concepts

Gravitational Potential Energy

When an object is positioned at a height above the ground, it possesses stored energy known as gravitational potential energy. This type of energy is based on its position relative to a reference point, usually the ground. You can think of it as the energy an object has due to its ability to fall. The higher the object, the more gravitational potential energy it holds.

The formula used to calculate gravitational potential energy (\( PE_g \)) is:

• \( PE_g = m \cdot g \cdot h \)

where:

• \( m \) is the mass of the object,
• \( g \) is the acceleration due to gravity (approximately \( 9.8 \ m/s^2 \) on Earth), and
• \( h \) is the height above the ground.

This energy decreases as the object descends because it is converting into kinetic energy. Understanding gravitational potential energy helps us comprehend how energy storage and release work in everyday situations such as a book falling off a shelf.

Kinetic Energy

Kinetic energy is the energy of motion. When an object is moving, it has kinetic energy. As an object initially at rest, like on a table, begins to fall, its gravitational potential energy is converted into kinetic energy, and it gains speed.

The amount of kinetic energy (\( KE \)) an object has can be calculated with the formula:

• \( KE = \frac{1}{2} m v^2 \)

where:

• \( m \) is the mass of the object and
• \( v \) is its velocity.

The faster the object moves, the more kinetic energy it possesses. This concept helps to explain various phenomena, such as why a speeding car causes more impact than a slow-moving one. As an object falls freely, its velocity increases until it hits the ground. At that point, the kinetic energy may be transformed into different forms, including sound and heat.

Energy Conversion

Energy conversion is the process of changing energy from one form to another. As an object falls, its energy transformation journey involves the conversion from gravitational potential energy to kinetic energy.

This transformation is not perfect, and energy conservation principles dictate that energy is never destroyed but converted instead. Upon impacting the ground, the object’s kinetic energy is converted into other forms:

• Some energy might become sound energy as the crash produces noise.
• Heat energy due to friction between the object and the ground.
• It might also cause deformation of the object or the surface, involving energy transfer into potential energy stored in deformed materials.

Understanding energy conversion allows us to explore various applications, from designing safer vehicles to harnessing renewable energy sources. It is a fundamental concept that’s crucial for analyzing systems and processes in physics and engineering.