E 7.1 Classifying work and Energy - Copy

What is work in physics?

Work is a change in state of a system caused by a force applied along a displacement.

What conditions determine whether work is done on an object?

Work is done when force and displacement are in the same direction; work is positive.

What happens if the force and displacement are perpendicular?

If the force and displacement are perpendicular to each other, work done is zero.

What signifies negative work?

Negative work occurs when the force is in the opposite direction of the displacement.

What are the three factors that determine work?

1. Force 2. Displacement 3. The angle between force and displacement (F and ∆d).

What is the SI unit of work?

The SI unit of work is the joule (J), where 1 joule equals a newton times a meter (N·m).

What does the work-energy theorem state?

The total work done on a system is equal to the change in the system's kinetic energy.

How does positive work affect kinetic energy?

If the total work done on a system is positive, then the kinetic energy increases.

How does negative work affect kinetic energy?

If the total work done on a system is negative, then the kinetic energy decreases.

What is kinetic energy?

Kinetic energy is energy due to motion.

What is potential energy?

Potential energy is energy due to the position or shape of an object.

What is pressure in physics?

Pressure is the magnitude of the perpendicular component of a force per unit area.

What is the connection between work and power?

Power is the rate at which work is done.

What is an isobaric process?

An isobaric process is a thermodynamic process in which pressure remains constant.

What happens when a gas expands against a movable piston?

The gas does positive work on the container walls during the expansion.

What is the relationship between mass, velocity, and kinetic energy?

Kinetic energy increases with mass and with the square of velocity.

What kind of force is exerted on an object when it is brought to a stop?

A friction force is exerted to bring the object to a stop.

How can the work done on a system be calculated?

The total work can be calculated by summing all the individual works done on the system.

Define energy in the context of physics.

Energy is the capacity or ability to do work, measured in joules (J).

What is the formula for calculating work (W)?

Work is calculated using the formula W = Fd cos(θ), where F is force, d is displacement, and θ is the angle between them.

What determines the direction of work done by a gas?

The direction of work done by a gas depends on whether the gas is expanding or contracting against a piston.

When is work considered zero?

Work is considered zero when there is no displacement or when the force is perpendicular to the direction of displacement.

What happens to energy when work is done on a system?

Energy is transferred into the system, resulting in a change in the system's kinetic energy.

What occurs when a system does positive work?

When a system does positive work, energy is transformed from the system to the surroundings.

Describe an energy bar chart.

An energy bar chart is a visual representation of the changes in a system's energy, allowing tracking of energy transformations.

What is the significance of the angle in work calculations?

The angle determines how much of the applied force contributes to the work done, with only the component in the direction of displacement being effective.