Chapter 6 - Work and Energy

Question 1

What type of quantity is work?

Answer 1

Scalar Quantity

Question 2

Formula for Work

Answer 2

W(work)=F(force)•s(displacement)

Question 3

Unit of work

Answer 3

Joule(J) = N(Newton)•s(meter)

Question 4

Work done when force is applied but displacement is zero?

Answer 4

Absolutely none

Question 5

Work done at an angle

Answer 5

W=(Fcosθ)s

Question 6

Result of work

Answer 6

Change in kinetic energy of an object

Question 7

Relationship that relates work in kinetic energy

Answer 7

Work-energy theorem

Question 8

Work-energy theorem expression

Answer 8

(ΣF)s=1/2mvᶠ²-1/2mvᴼ²

Question 9

Equation for the kinetic energy of an object

Answer 9

KE=1/2mv²

Question 10

Why does a moving object have Kinetic Energy?

Answer 10

A moving object has kinetic energy because work was done to accelerate the object from rest to a speed vᶠ

Question 11

When does the work-energy theorem not work?

Answer 11

The work-energy theorem deals with the work done by the net external force. The work-energy theorem does not apply to the work done by an individual force, unless that force happens to be the only one present, in which case it is the net force.

Question 12

Formula pertaining to work done by gravity/potential energy

Answer 12

W(gravity)=mg(ho-hf)

Question 13

Energy possessed by an object in motion

Answer 13

Kinetic Energy

Question 14

Energy an object possessed by virtue of its position relative to the earth

Answer 14

Gravitational Potential Energy

Question 15

The greater the height, the greater is the potential to do work, meaning?

Answer 15

The greater is the Gravitational Potential Energy

Question 16

Formula for Gravitational potential energy

Answer 16

PE=mgh

Question 17

A force is __ when work it does on a moving object is independent of the path between the object’s initial and final positions; A force is __ when it does no net work on an object moving around a closed path, starting and finishing at the same point

Answer 17

Conservative force

Question 18

Potential energy in a closed path

Answer 18

0J

Question 19

A force is _ if the work it does on an object moving between two points depends on the path of motion between two points, such as kinetic frictional force.

Answer 19

Nonconservative force

Question 20

Formula for net work done by nonconservative force

Answer 20

Wnc = (KEf - KE0 ) + (PEf - PE0 ) or Wnc = ΔKE + ΔPE

Question 21

Sum of Kinetic energy and gravitational potential energy

Answer 21

Total Mechanical Energy

Question 22

Equation for Total Mechanical Energy

Answer 22

Wnc = (KEf + PEf) - (KE0 + PE0) or Wnc = Ef - E0

Question 23

Principle of Conservation of Mechanical Energy states that

Answer 23

Total mechanical energy is conserved when Wnc=0

Question 24

A term that incorporates both work and time

Answer 24

Power

Question 25

Equation for Power

Answer 25

P= Work/ Time

Question 26

Unit for Power

Answer 26

Joule / Second = Watt

Question 27

The rate at which the energy is changing

Answer 27

Power

Question 28

Energy can neither be created or destroyed, but can only be converted from on form to another.

Answer 28

The principle of conservation of energy