Energy and Equilibrium

Question 1

torque

Answer 1

is a measure of a force’s ability to cause rotational acceleration

Question 2

if a net force acts on an objects center of mass

Answer 2

the object accelerates translationally

Question 3

If a net force acts on any other spot than the center of mass

Answer 3

the objects accelerates rotationally

Question 4

is torque a vector or scalar

Answer 4

vector

Question 5

lever arm

Answer 5

where one side has a force acting at 90degrees and the other at some other force making sin 90=1

Question 6

the greater the net torque on an object the greater

Answer 6

its acceleration

Question 7

torque increases as

Answer 7

the component of the force acting perpendicular to the position vector increases
as the distance between the point of application of the force and the point of rotation increase

Question 8

a system is in equilibrium if

Answer 8

the translational velocity of its center of mass and the angular velocities of all its parts are constant

Question 9

if all velocities acting on the object are zero

Answer 9

static equilibrium

Question 10

if any velocities are nonzero but all the velocities are constant

Answer 10

dynamic equilibrium

Question 11

terminal velocity for a skydiver

Answer 11

when the gravitational downward force is equal to the force of air resistance upward

Question 12

isolated system

Answer 12

cannot exchange mass or work and heat

Question 13

open system

Answer 13

can exchange work, heat, and mass with the surroundings

Question 14

closed system

Answer 14

can exchange work and heat with the surroundings but cannot exchange mass

Question 15

joule units

Answer 15

1kgm^2/s^2

Question 16

mechanical energy vs non-mechanical energy

Answer 16

mechanical energy is energy on the macroscopic level while non-mechanical energy is energy on the microscopic level

Question 17

gravitational potential energy

Answer 17

is the energy created by the force of gravity

Question 18

heat

Answer 18

is energy that is transferred between a system and its surroundings due to a temperature difference between them

Question 19

work

Answer 19

is energy transferred for any reason other than a temperature difference. Is scalar and is measured in units of energy (joules)

Question 20

First law of thermodynamics equation accounting for energy

Answer 20

W+q = change in energy

Question 21

Energy total equals the sum of all forms of energy in that system

Answer 21

change in energy total= Emechanical+Einternal

Question 22

Equation for energy ignoring internal energy because internal energy is measured by friction

Answer 22

W+q=change in K +change in U

Question 23

Work-kinetic energy theorem

Answer 23

W= change in kinetic energy

Question 24

work done by a system

Answer 24

negative value for work

Question 25

work done on a system

Answer 25

positive value for work

Question 26

power equations

Answer 26

rate of energy transfer P=w/t P=E/t (E=energy change of the system which equals work plus heat)

Question 27

power unit

Answer 27

watt (J/s)

Question 28

conservative forces result in

Answer 28

zero change in energy in the system

Question 29

does a conservative force do work

Answer 29

no because there is not any work lost or gained in the system

Question 30

non-conservative forces equals the

Answer 30

change in mechanical energy of the systems upon which they are applied W=change in K+change in U

Question 31

for energy equations

Answer 31

if there is a heat or pressure-volume change then it is a thermodynamic problem. If not then it is a transfer of work