What is energy?

**What is Energy?**

Energy is the capacity to do work or produce change. It can exist in various forms and can be transformed from one form to another but cannot be created or destroyed, according to the law of conservation of energy.

### The two main types of energy are kinetic and potential energy.

**Kinetic Energy:**
Kinetic energy is the energy that an object possesses due to its motion. It depends on the mass of the object and the square of its velocity. The formula for kinetic energy (KE) is given by:

\[ KE = \frac{1}{2}mv^2 \]

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

**Potential Energy:**
Potential energy is the energy that an object possesses due to its position or state. It is stored energy that has the potential to be converted into kinetic energy. The most common type of potential energy is gravitational potential energy, which depends on the height of an object above a reference point (usually the ground). The formula for gravitational potential energy (PE) is given by:

\[ PE = mgh \]

where \( m \) is the mass of the object, \( g \) is the acceleration due to gravity, and \( h \) is the height of the object above the reference point.

### What does potential energy depend on?

Potential energy depends on several factors, including:
- The mass of the object (more mass means more potential energy).
- The height of the object above a reference point (greater height means more potential energy).
- The gravitational field strength (in different gravitational fields, the potential energy for the same mass and height will differ).

### What has more potential energy - a ball on the ground or a ball on the top of a ladder?

A ball at the top of a ladder has more potential energy compared to a ball on the ground. This is because the ball at the top of the ladder is at a greater height, which increases its gravitational potential energy.

### Explain how the kinetic and potential energy of a ball changes as it is thrown up into the air.

As a ball is thrown up into the air, its energy transformations are as follows:

1. **At the moment of release**: Right when the ball is thrown, it has maximum kinetic energy and minimal potential energy (assuming it's starting from a low height).

2. **As it rises**: As the ball ascends, its speed decreases due to the effect of gravity acting downwards, which means its kinetic energy decreases. As its height increases, its potential energy increases because it is moving further from the ground.

3. **At the highest point**: At the peak of its trajectory, the ball has zero kinetic energy (it momentarily stops) and maximum potential energy, since it is at its highest elevation.

4. **As it falls back down**: As the ball falls, its potential energy decreases (as it is getting closer to the ground), while its kinetic energy increases as it speeds up due to the acceleration of gravity.

Throughout this process, the total mechanical energy (kinetic + potential) remains constant, assuming no energy is lost to air resistance or other forms of energy dissipation.

Can you now shorten and simplify that all into 1-2 sentences

Energy is the capacity to do work and exists mainly as kinetic energy (the energy of motion) and potential energy (stored energy based on position). A ball thrown upwards transforms kinetic energy into potential energy as it rises, reaching maximum potential energy at its highest point, and then reverses back to kinetic energy as it falls.

can you shorten all of those answers into 1-2 sentences

Energy is the capacity to do work and exists primarily as kinetic energy (energy of motion) and potential energy (stored energy based on position). Potential energy depends on an object's mass and height, with a ball on top of a ladder having more potential energy than one on the ground; as a ball is thrown upward, its kinetic energy decreases while its potential energy increases until it peaks, after which the energy transformations reverse as it falls.

What is energy?

The two main types of energy are kinetic and potential energy. Define them both:

Kinetic energy-

Potential energy-

What does potential energy depend on?

What has more potential energy- a ball on the ground or a ball on the top of a ladder?

Explain how the kinetic and potential energy of a ball changes as it is thrown up into the air?

**What is energy?**

Energy is the capacity to do work or produce change, existing in various forms.

### The two main types of energy are kinetic and potential energy.

**Kinetic Energy:**
Kinetic energy is the energy an object possesses due to its motion, calculated using the formula \( KE = \frac{1}{2} mv^2 \), where \( m \) is mass and \( v \) is velocity.

**Potential Energy:**
Potential energy is the stored energy in an object based on its position or configuration, commonly represented as gravitational potential energy, calculated with \( PE = mgh \), where \( m \) is mass, \( g \) is gravitational acceleration, and \( h \) is height.

### What does potential energy depend on?
Potential energy depends on the object's mass, height above a reference point, and the gravitational field strength.

### What has more potential energy - a ball on the ground or a ball on the top of a ladder?
A ball on the top of a ladder has more potential energy than a ball on the ground due to its greater height.

### Explain how the kinetic and potential energy of a ball changes as it is thrown up into the air.
As a ball is thrown upwards, its kinetic energy decreases and potential energy increases until it reaches its highest point (maximum potential energy, zero kinetic energy), then reverses as it falls, gaining kinetic energy while losing potential energy.

can you shorten each answer into its own sentence

**What is energy?**

Energy is the capacity to do work or produce change.

### The two main types of energy are kinetic and potential energy.

**Kinetic Energy:**
Kinetic energy is the energy an object has due to its motion.

**Potential Energy:**
Potential energy is the stored energy of an object based on its position.

### What does potential energy depend on?
Potential energy depends on an object's mass, height, and gravitational field strength.

### What has more potential energy - a ball on the ground or a ball on the top of a ladder?
A ball on the top of a ladder has more potential energy than a ball on the ground.

### Explain how the kinetic and potential energy of a ball changes as it is thrown up into the air.
As a ball is thrown upward, its kinetic energy decreases while its potential energy increases until it reaches the highest point before reversing during its descent.

Label the highest and lowest points of kinetic and potential energy on the diagram below. (Hint- they are opposite. When KE is highest, PE is lowest and vice versa.) Question #2 on page 8 will help with this.

100% PE - top of picture
50% PE - halfway at the picture
50% KE - halfway at the picture
100%KE - bottom of picture

To label the highest and lowest points of kinetic and potential energy based on your description:

1. **At the top of the picture (100% PE):** This point has the maximum potential energy and the lowest kinetic energy (0% KE).

2. **At the halfway point going up (50% PE):** Here, the potential energy is decreasing, and the kinetic energy is still increasing.

3. **At the halfway point going down (50% KE):** At this point, the kinetic energy is still increasing as the ball descends, and the potential energy is decreasing.

4. **At the bottom of the picture (100% KE):** This point has the maximum kinetic energy and the lowest potential energy (0% PE).

So, summarizing:
- **Top of the picture:** 100% PE (0% KE)
- **Halfway going up:** 50% PE and 50% KE
- **Halfway going down:** 50% KE and 50% PE
- **Bottom of the picture:** 100% KE (0% PE)

Feel free to ask more questions if you need further clarification!