Question

The displacement d (in meters) of an object at time t (in seconds) is given.

d= -sin(t/9)

(a) Describe the motion of the object.
is it simple harmonic motion or damped motion?

(b) What is the maximum displacement from its resting position? Round your answer to two decimal places.
in meters
(c) What is the time required for one oscillation? Round your answer to two decimal places.
in seconds
(d) What is the frequency? Round your answer to two decimal places.
in oscillation/second

Answer 1

simple harmonic i believe; there is no part of it that is accounting for a dampned effect

Answer 2

1 is the max displacement

Answer 3

the displacement from rest is the amplitude; which is 1

the initial displacement tho is -1

Answer 4

it asks for decimal places tho?

Answer 5

initial disp is 0 amistre

Answer 6

1.0000 then lol

Answer 7

hahaha

Answer 8

hahaha

Answer 9

well.... yeah, initial = 0 :)

Answer 10

1/18pi is the frequency

Answer 11

and hence18pi is the time period for one oscillation

Answer 12

so max disp is 0 or 1?

Answer 13

1

Answer 14

are you accounting for the pi already in the problem? or are you atributing an external pi?

Answer 15

sin[(1/9)t]

Answer 16

see the eqn for shm is x=sin (wt)

Answer 17

and
2(pi)f=w

Answer 18

lol i got lost

Answer 19

so f=w/2pi

Answer 20

w=1/9 hence f = 1/18pi

Answer 21

i get turned around whe w = pi/n lol

Answer 22

and since T=1/f , T=18pi

Answer 23

http://www.wolframalpha.com/input/?i=-sin%28t%2F9%29

hims good on it

Answer 24

yeah waves were my forte ;)

Answer 25

so was c) 18pi ?

Answer 26

yes

Answer 27

did u follow the working?

Answer 28

lol got lost

Answer 29

would you mind explaining it to me?

Answer 30

do u know what simple harmonic motion is?

Answer 31

i did it before but forgot. is it got to do with the pendulums?

Answer 32

yeah...anything in shm follows the displacement eqn
x = Asin(wt)
w is called the angular frequency and equals 2pi x f
where f is the frequency

Answer 33

and f=1/T
where T is the time for one cycle or oscillation

Answer 34

i remember now haha

Answer 35

max disp from its resting position isnt 1 tho

Answer 36

then what?

Answer 37

-1?

Answer 38

im not sure. but the answer u got is 1.00? its not right for some reason

Answer 39

so its -1?

Answer 40

is it -1.00??

Answer 41

must be that then...

Answer 42

no it isn't.

Answer 43

it must be to two dp and be in meters

Answer 44

gotta be 1.00...dunno y its coming out wrong..

Answer 45

me either but it aint working. tried it already

Answer 46

cud it be 0

Answer 47

how do u work that part anyways?

Answer 48

hey amistre, the max disp from rest is turnin out wrong

Answer 49

i put in -1.00 and 1.00 both r wrong

Answer 50

thats becasue we assumed displacement = amplitude

d = displacement; so we gotta work the formula :)

Answer 51

amplitude is defined as the max displacemnt from the mean position

Answer 52

it peaks at |+-1|

it aint asking for the value of 't' at the max becasue there aint no interval to associate a single t into

Answer 53

have you tried it without the decimals?

Answer 54

just enter: 1

Answer 55

its my last shot tho lol

Answer 56

nah, it didnt work