exam 3

Question 1

when position is at positive amplitude

Answer 1

velocity is zero and acceleration is negative

Question 2

when position is at negative amplitude

Answer 2

velocity is zero and acceleration is positive

Question 3

when a spring is stretched, what is the force equation

Answer 3

F = -kx

Question 4

what is a simple pendulum

Answer 4

physical pendulum with mass at the end

Question 5

what is one total oscillation

Answer 5

when a spring bounces down and back up

Question 6

where is the amplitude on a sinusoidal graph

Answer 6

the highest point

Question 7

what is simple harmonic motion

Answer 7

motion driven by a spring oscillating back and forth

Question 8

what is x in simple harmonic motion

Answer 8

displacement from equilibrium

Question 9

why is the spring constant k negative

Answer 9

the spring exerts a force to try and pull it back to equilibrium

Question 10

where is the equilibrium point of a spring without mass

Answer 10

x = 0

Question 11

where is the equilibrium point of a spring with a mass

Answer 11

x = -mg/k

Question 12

what is the force that is exerted in the opposite direction of mg for a spring

Answer 12

-kx

Question 13

what is the relationship between the sinusoidal position graph and acceleration graph

Answer 13

opposites/flipped upside down

Question 14

when position is at zero

Answer 14

velocity is at maximum and acceleration is zero

Question 15

where is the point particle/center of mass on a simple pendulum

Answer 15

at the end, opposite end of rotational axis

Question 16

how does beta B affect the speed of the object

Answer 16

smaller beta B means the object will roll faster

Question 17

what is c

Answer 17

ratio of KErot to KEtrans

Question 18

what does the smallest c ratio mean

Answer 18

minimizing rotational motion and maximizing translational motion

Question 19

what is the agent of change in linear motion

Answer 19

force F

Question 20

what is the agent of change in angular motion

Answer 20

Torque T

Question 21

when can we model an object as a point particle

Answer 21

when the object is far away from the axis of rotation, relative to its size

Question 22

what is the rotational motion for an object with n to infinity particle

Answer 22

in a circular path with a radius r from the axis of rotation

Question 23

what is rotational inertia

Answer 23

moment of inertia

Question 24

which angular motions are instantaneous and why

Answer 24

angular velocity and angular acceleration because they are found by taking derivatives

Question 25

when is the net torque zero

Answer 25

angle is 180 or forces are antiparallel

Question 26

what does torque change

Answer 26

angular momentum

Question 27

how can a figure skater change her rotational inertia

Answer 27

rearranging her body

Question 28

what is a rigid body

Answer 28

an object that maintains the same shape, but can rotate

Question 29

how do we determine rotation axis

Answer 29

the centers of all of the circles that the points on the rigid object rotate about

Question 30

where is r measured

Answer 30

from the axis of rotation to the force

Question 31

when is momentum conserved

Answer 31

the external net forces equal zero and mass is constant

Question 32

what is the equation for thrust

Answer 32

Thrust = ma

Question 33

elastic collisions

Answer 33

objects are the same before and after, they spring/snap back to what they looked like

Question 34

inelastic collisions

Answer 34

objects are different before and after, change shape/deform and make a noise

Question 35

perfectly inelastic

Answer 35

objects stick together or one objects splits apart

Question 36

what must happen for collision system’s momentum to be conserved

Answer 36

the sum of the external forces must equal zero

Question 37

what is newton’s third law of motion

Answer 37

for every reaction there is an equal and opposite reaction, forces cancel

Question 38

why don’t the internal forces the two objects exert on each other contribute to a non-zero net force

Answer 38

newton’s third law says that for every force there is an equal and opposite force

Question 39

what type of collision is kinetic energy conserved

Answer 39

elastic