Test 3 Ch.'s 12, 14, and 20

Question 1

What is a rigid body?

Answer 1

a point on a body maintains its position relative to all other points on the body

Question 2

CCW angular momentum

Answer 2

angular momentum is in the + z direction

Question 3

CW angular momentum

Answer 3

angular momentum is in the - z direction

Question 4

Parallel axis theorem

Answer 4

if you know the moment of inertia and want to rotate an object about something other than the center of bass;
I=I(center of mass) + md^2

Question 5

What is angular velocity(omega) in terms of linear velocity?

Answer 5

omega=v/r

Question 6

Right hand rule for torque

Answer 6

thumb: r
index finger: F
middle finger: torque

Question 7

What must be satisfied for an object to be in static equilibrium?

Answer 7

Fnet=0 in the x, y and z directions

and net torque=0

Question 8

equation for net torque

Answer 8

rFsin(theta)

Question 9

When a spring is compressed;

Answer 9

velocity=0
max potential energy
kinetic energy=0
max force
max acceleration

Question 10

When spring is at equilibrium;

Answer 10

max kinetic energy
potential energy=0
max velocity
Force=0

Question 11

When spring is extended;

Answer 11

velocity=0
max potential energy
kinetic energy=0
max force
max acceleration

Question 12

Amplitude

Answer 12

max displacement from equilibrium

measured in meters

Question 13

Frequency

Answer 13

cycles per second

unit of hertz

Question 14

Period(T)

Answer 14

time for 1 cycle

Question 15

angular frequency

Answer 15

omega

units of rad/s

Question 16

Restoring force

Answer 16

always points back towards equilibrium

Question 17

Relationship between period and frequency

Answer 17

T=1/f

Question 18

Equation for velocity in terms of simple harmonic motion

Answer 18

Vmax=sqrt(k/m)A=omegaA

Question 19

What is angular frequency equal to in torsional SHM?

Answer 19

sqrt(k/I)

Question 20

What is a simple pendulum?

Answer 20

assumes all the mass is at the end of the pendulum

Question 21

3 cases of a damped oscillator

Answer 21

under damped
critically damped
over damped

Question 22

What is a mechanical wave?

Answer 22

disturbance in a material(medium)

Question 23

What effect does a mechanical wave have on the medium?

Answer 23

it causes the medium to under go SHM

Question 24

What does a wave actually move?

Answer 24

ENERGY

Question 25

Transverse wave

Answer 25

amplitude is perpendicular to the velocity of the wave

Question 26

Longitudinal wave

Answer 26

amplitude is parallel to the velocity of the wave

Question 27

In the equation for a wave: kx-omega*t

What direction is the wave going?

Answer 27

postive x direction

Question 28

In the equation for a wave: kx+omega*t

What direction is the wave going?

Answer 28

negative x direction

Question 29

what is the weird u equal to?

Answer 29

m/L where L is the length of the medium

Question 30

Velocity of a wave on a string

Answer 30

sqrt(T/wierd u) where T is tension

Question 31

Constructive interference

Answer 31

two waves come together and double

Question 32

destructive interference

Answer 32

two waves come together and cancel out each other’s amplitude but not each other’s energy

Question 33

How many nodes and antinodes in the 2nd harmonic?

Answer 33

2 antinodes and 1 node

Question 34

How many nodes and antinodes in the 1st overtone?

Answer 34

2 antinodes and 1 node

Question 35

linear terms to rotational terms

Answer 35

x->theta
v->omega
a-> alpha
m->I (uppercase i, moment of inertia)
F-> torque
P(momentum)-> L (angular momentum)

Question 36

Equation for rotational kinetic energy

Answer 36

K=(1/2)Iomega^2

Question 37

Definition of torque

Answer 37

a force that causes rotation

Question 38

Wave # k=

Answer 38

(2*pi)/wavelength