PS 04.1A Work and Machines

What is the primary function of a machine?

• To create energy

• To make work easier

• To increase work

• To eliminate work

Answer explanation

The primary function of a machine is to make work easier. Machines help reduce the effort needed to perform tasks, allowing us to accomplish more with less energy.

Fill in the blank: A machine is a device that helps make ______ easier.

• work

• play

• rest

• sleep

Answer explanation

A machine is designed to assist in performing tasks, making work easier and more efficient. The other options, play, rest, and sleep, do not align with the primary function of machines.

Which of the following best describes how machines change work?

• They increase the amount of work done.

• They decrease the amount of work done.

• They change the direction or magnitude of a force.

• They eliminate the need for energy.

Answer explanation

Machines change work by altering the direction or magnitude of a force, making tasks easier or more efficient. They do not eliminate the need for energy or decrease the total work done.

Tags

NGSS.HS-PS2-1

Machines are used to make work easier by changing the ______ of a force.

• direction

• color

• temperature

• size

Answer explanation

Machines make work easier by changing the direction of a force, allowing us to apply force more effectively. This is why 'direction' is the correct choice, as it directly relates to how machines assist in performing tasks.

Tags

NGSS.HS-PS2-1

What is the term used to describe the ability of a machine to convert input energy into useful output energy?

• Work

• Efficiency

• Mechanical Advantage

• Compound Machine

Answer explanation

The term 'Efficiency' describes how well a machine converts input energy into useful output energy. It measures the ratio of useful work output to total energy input, indicating the effectiveness of the machine.

Tags

NGSS.HS-PS3-3

A _______ is a device that makes work easier by changing the size or direction of a force.

• A) Simple Machine

• B) Compound Machine

• C) Efficiency

• D) Work

Answer explanation

A Simple Machine is designed to make work easier by altering the size or direction of a force, which fits the definition provided in the question. Other options do not accurately describe this function.

What is the definition of 'force'?

• A type of energy

• A push or pull exerted on an object

• A form of matter

• A state of rest.

Answer explanation

The correct definition of 'force' is 'a push or pull exerted on an object.' This describes how forces interact with objects, influencing their motion or state.

Fill in the blank: A 'force' is a _______ exerted on an object.

• A) type of energy

• B) push or pull

• C) form of matter

• D) state of rest

Answer explanation

A 'force' is defined as a 'push or pull' exerted on an object, making option B the correct choice. It describes the interaction that can change the motion of an object, unlike the other options which do not fit this definition.

What is the definition of 'work' in physics?

• The use of energy to create heat

• The use of force to move an object

• The use of power to generate electricity

• The use of speed to travel distances.

Answer explanation

In physics, 'work' is defined as the use of force to move an object over a distance. This aligns with the correct answer, as it emphasizes the relationship between force and movement, unlike the other options.

In physics, work is done when you use force to ______ an object.

• stop

• move

• hold

• lift

Answer explanation

In physics, work is defined as the process of using force to move an object. While stopping, holding, or lifting may involve force, only moving an object results in work being done according to the work-energy principle.