Work and Energy Vocabulary

Chapter 4: Work and Energy (Wednesday)

Vocabulary

• Machine: An apparatus using mechanical power and having parts each with a definite function and together performing a task.

• Compound Machine: A machine that combines two or more simple machines to perform a task.

• Mechanical Advantage: The ratio of the output force produced by a machine to the input force applied to it. It is a measure of how much the machine multiplies the applied force.

• System: A set of connected things or parts forming a complex whole, especially a body or an organization.

• Potential Energy: The energy possessed by a body by virtue of its position relative to others, stresses within itself, electric charge, and other factors.

• Chemical Potential Energy: Energy stored in the chemical bonds of compounds.

• Law of Conservation of Energy: Energy cannot be created or destroyed, but only changed from one form into another or transferred from one object to another. The total energy of an isolated system remains constant.

• Power: The rate at which work is done or energy is transferred.

Math Equations to Know

• Work: The product of the force applied to an object and the distance over which it moves in the direction of the force.

• Simple Machine: A basic mechanical device that reduces the amount of force required to perform work; examples include levers, pulleys, inclined planes, wedges, screws, and wheels and axles.

• Efficiency: The ratio of useful work output to total work input, expressed as a percentage. It represents how effectively a machine converts input energy into useful output energy.

• Energy: The capacity to do work.

• Kinetic Energy: The energy possessed by an object due to its motion.

• Elastic Potential Energy: Energy stored in a deformable object, such as a spring or rubber band, when it is stretched or compressed.

• Gravitational Potential Energy: Energy possessed by an object due to its height above a reference point.

• Mechanical Energy: The sum of kinetic and potential energy in a system. It is the energy associated with the motion and position of an object.

Equations

• Work: \text{Work} = \text{Force} \times \text{Distance}

• Power: \text{Power} = \frac{\text{Work done}}{\text{Time needed}}

• Mechanical Advantage: \text{Mechanical Advantage} = \frac{\text{Output Force}}{\text{Input Force}}

• Efficiency: \text{Efficiency \%} = \frac{\text{Output Work}}{\text{Input Work}} \times 100

• Force: \text{Force} = \frac{\text{Work}}{\text{Distance}}

• Kinetic Energy: \text{KE} = \frac{1}{2}mv^2

• Gravitational Potential Energy: \text{GPE} = mgh

Overall Concepts

• Work: Work is defined as force applied through a distance; if there is no displacement, no work is done.

• Power: Power is the rate at which work is done. It measures how quickly energy is transferred or converted.

• Machines: Machines make work easier by multiplying force, increasing speed, or changing the direction of the force. There are 6 simple machines:

  • Lever

  • Pulley

  • Screw

  • Wheel and Axle

  • Wedge

  • Inclined Plane (Ramp)

• Machines can:

  1. Increase speed

  2. Change the direction of the force

  3. Increase force

• Efficiency: Efficiency is the ratio of the work output to the work input. It is always less than 100% due to energy losses from friction, heat, and other factors.

• Mechanical Advantage (MA): Mechanical advantage is the ratio of output force to input force. Ideally, you want MA to be greater than 1, meaning the machine multiplies the input force resulting in a greater output force.

• Energy: Energy is the ability to cause change. It exists in various forms.

• Kinetic vs. Potential Energy:

  • Kinetic Energy: Energy of motion.

  • Potential Energy: Stored energy. Types of potential energy include:

    • Elastic (e.g., a stretched spring)

    • Chemical (e.g., energy stored in fuels or food)

    • Gravitational (e.g., energy due to an object's height)

• Law of Conservation of Energy: A fundamental principle stating that energy cannot be created or destroyed; it can only be converted from one form to another. A basic example is the conversion between potential and kinetic energy and back.

Chapter 4: Work and Energy (Wednesday) ### Vocabulary - **Machine:** An apparatus using mechanical power and having parts each with a definite function and together performing a task. - **Compound Machine:** A machine that combines two or more simple machines to perform a task. - **Mechanical Advantage:** The ratio of the output force produced by a machine to the input force applied to it. It is a measure of how much the machine multiplies the applied force. - **System:** A set of connected things or parts forming a complex whole, especially a body or an organization. - **Potential Energy:** The energy possessed by a body by virtue of its position relative to others, stresses within itself, electric charge, and other factors. - **Chemical Potential Energy:** Energy stored in the chemical bonds of compounds. - **Law of Conservation of Energy:** Energy cannot be created or destroyed, but only changed from one form into another or transferred from one object to another. The total energy of an isolated system remains constant. - **Power:** The rate at which work is done or energy is transferred. ### Math Equations to Know - **Work:** The product of the force applied to an object and the distance over which it moves in the direction of the force. - **Simple Machine:** A basic mechanical device that reduces the amount of force required to perform work; examples include levers, pulleys, inclined planes, wedges, screws, and wheels and axles. - **Efficiency:** The ratio of useful work output to total work input, expressed as a percentage. It represents how effectively a machine converts input energy into useful output energy. - **Energy:** The capacity to do work. - **Kinetic Energy:** The energy possessed by an object due to its motion. - **Elastic Potential Energy:** Energy stored in a deformable object, such as a spring or rubber band, when it is stretched or compressed. - **Gravitational Potential Energy:** Energy possessed by an object due to its height above a reference point. - **Mechanical Energy:** The sum of kinetic and potential energy in a system. It is the energy associated with the motion and position of an object. ### Equations - Work: \text{Work} = \text{Force} \times \text{Distance} - Power: \text{Power} = \frac{\text{Work done}}{\text{Time needed}} - Mechanical Advantage: \text{Mechanical Advantage} = \frac{\text{Output Force}}{\text{Input Force}} - Efficiency: \text{Efficiency \%} = \frac{\text{Output Work}}{\text{Input Work}} \times 100 - Force: \text{Force} = \frac{\text{Work}}{\text{Distance}} - Kinetic Energy: \text{KE} = \frac{1}{2}mv^2 - Gravitational Potential Energy: \text{GPE} = mgh ### Overall Concepts - **Work:** Work is defined as force applied through a distance; if there is no displacement, no work is done. - **Power:** Power is the rate at which work is done. It measures how quickly energy is transferred or converted. - **Machines:** Machines make work easier by multiplying force, increasing speed, or changing the direction of the force. There are 6 simple machines:- Lever - Pulley - Screw - Wheel and Axle - Wedge - Inclined Plane (Ramp) - **Machines can:**1. Increase speed 2. Change the direction of the force 3. Increase force - **Efficiency:** Efficiency is the ratio of the work output to the work input. It is always less than 100% due to energy losses from friction, heat, and other factors. - **Mechanical Advantage (MA):** Mechanical advantage is the ratio of output force to input force. Ideally, you want MA to be greater than 1, meaning the machine multiplies the input force resulting in a greater output force. - **Energy:** Energy is the ability to cause change. It exists in various forms. - **Kinetic vs. Potential Energy:** - **Kinetic Energy:** Energy of motion. - **Potential Energy:** Stored energy. Types of potential energy include:- Elastic (e.g., a stretched spring) - Chemical (e.g., energy stored in fuels or food) - Gravitational (e.g., energy due to an object's height) - **Law of Conservation of Energy:** A fundamental principle stating that energy cannot be created or destroyed; it can only be converted from one form to another. A basic example is the conversion between potential and kinetic energy and back. - **Classes of Levers:** Levers are classified into three classes based on the relative positions of the fulcrum, effort (input force), and load (output force): - **Class 1 Levers:** - The fulcrum is located between the effort and the load. - Examples include seesaws, scissors, and crowbars. - These levers can provide either mechanical advantage or increase the distance over which the load moves, depending on the position of the fulcrum. - **Class 2 Levers:** - The load is located between the fulcrum and the effort. - Examples include wheelbarrows, nutcrackers, and bottle openers. - Class 2 levers always provide a mechanical advantage (MA > 1), meaning the output force is greater than the input force. - **Class 3 Levers:*