Physics Chapter 2: Work and Energy (2 Stars)

Question 1

_____ is the property of a system that enables it to do something or make something happen, including the capacity to do work. The SI units for all forms of energy are joules (J).

Answer 1

Energy

Question 2

______ is energy associated with the movement of objects. It depends on mass and speed squared (not velocity).

Answer 2

Kinetic energy

Question 3

______ is energy stored within a system. It exists in gravitational, elastic, electrical, and chemical forms.

Answer 3

Potential energy

Question 4

______ is related to the mass of an object and its height above a zero-point, called a datum.

Answer 4

Gravitational potential energy

Question 5

______ is related to the spring constant (a measure of the stiffness of a spring) and the degree of stretch or compression of a spring squared.

Answer 5

Elastic potential energy

Question 6

Electrical potential energy exists between ______ particles.

Answer 6

charged

Question 7

_________ is the energy stored in the bonds of compounds.

Answer 7

Chemical potential energy

Question 8

_________ of a system is the sum of its kinetic and potential energies.

Answer 8

The total mechanical energy

Question 9

_______ are path independent and do not dissipate the mechanical energy of a system.

Answer 9

Conservative forces

Question 10

If only conservative forces are acting on an object, the total mechanical energy is _____

Answer 10

conserved.

Examples of conservative forces include gravity and electrostatic forces. Elastic forces, such as those created by springs, are nearly conservative.

Question 11

______ are path dependent and cause dissipation of mechanical energy from a system.

Answer 11

Nonconservative forces

Examples of nonconservative forces include friction, air resistance and viscous drag.

Question 12

While total energy is conserved, some mechanical energy is lost as ______ or chemical energy.

Answer 12

thermal

Question 13

_____ is a process by which energy is transferred from one system to another.

Answer 13

Work

Question 14

Work may be expressed as the dot product of force and displacement, or the product of force and distance traveled with the ______ of the angle between the two.

Answer 14

cosine

Question 15

____ may also be expressed as the area under a pressure–volume (P–V) curve.

Answer 15

Work

Question 16

____ is the rate at which work is done or energy is transferred. The SI unit for power is the watt (W).

Answer 16

Power

Question 17

The work–energy theorem states that when net work is done on or by a system, the system’s ______ will change by the same amount. In more general applications, the work done on or by a system can be transferred to other forms of energy as well.

Answer 17

kinetic energy

Question 18

_____ is the factor by which a simple machine multiplies the input force to accomplish work.

Answer 18

Mechanical advantage

Question 19

The six simple machines are the inclined plane, wedge, wheel and axle, lever, pulley, and screw. Simple machines provide the benefit of ________

Answer 19

mechanical advantage.

Question 20

Mechanical advantage makes it easier to accomplish a given amount of _____ because the input force necessary to accomplish the work is reduced; the distance through which the reduced input force must be applied, however, is increased by the same factor (assuming 100% efficiency).

Answer 20

work

Question 21

The load is the output force of a simple machine, which acts over a given load distance to determine the work output of the simple machine. The effort is the input force of a simple machine, which acts over a given effort distance to determine the ____ input of the simple machine.

Answer 21

work

Question 22

______ is the ratio of the machine’s work output to work input when nonconservative forces are taken into account.

Answer 22

Efficiency