Kinetic Energy and Work Review

These flashcards cover key concepts related to kinetic energy, work, and their relationships, which are fundamental for understanding mechanics.

What is energy?

Energy is a scalar quantity associated with the state of one or more objects.

Name the types of energy transformations.

Energy can be transformed between mechanical, chemical, electromagnetic, heat, nuclear, etc.

What is the SI unit of kinetic energy?

The SI unit of kinetic energy is the joule (J). 1 joule = 1 kg×m²/s².

How is kinetic energy defined?

Kinetic energy K is the energy associated with the state of motion of an object.

What is the relationship between speed and kinetic energy?

The faster an object moves, the greater its kinetic energy.

What is work?

Work W is energy transferred to or from an object by means of a force acting on the object.

What is positive work?

Positive work is energy transferred to the object.

What is negative work?

Negative work is energy transferred from the object.

What is the work-kinetic energy theorem?

The work-kinetic energy theorem states that the change in kinetic energy of a particle is the net work done on the particle.

Explain how work is calculated when multiple forces are involved.

The net work done on the object is the sum of the works done by the individual forces.

Define Hooke's Law for spring force.

The spring force is proportional to the displacement from its relaxed position, indicated by the negative sign which shows it acts opposite to the displacement.

How is work done by a spring calculated?

The net work done by a spring is positive if the block ends up closer to the relaxed position, negative if farther away, and zero if at the same distance.

What is the formula for work done by a constant force?

For a constant force, the work done W is calculated as W = F · d · cos(θ).

Define power in the context of work.

Power is the time rate at which work is done.

What is the unit of power?

The SI unit of power is the watt (W), equivalent to one joule per second.

How can the work done by a variable force be calculated graphically?

The work done by a variable force can be calculated as the area under the force versus displacement graph.