Question

Help please
http://prntscr.com/1226g3

Answer 1

i have solve a and b i need help with part c

Answer 2

for "c" , we are looking for "t" just like in (b) but negative

Answer 3

so
\[h = -1=7\cos\left({\pi\over3}t\right)\\
t={3\over\pi}\cos^{-1}(-1/7)=?
\]

Answer 4

93.7

Answer 5

no. I got 1.64s

Answer 6

-1=7cos(3t/pi)
t=1.79 secs

Answer 7

well + or - 1.79 but time has to be positive

Answer 8

for your case

Answer 9

and it says for the "second time". So, to that, you add the comeplete period

Answer 10

now, the period of oscillation for this is : \[T={3\over2}=1.5s\]

Answer 11

-3=7cos(3t/pi)
t=2.1087

Answer 12

iam getting more confused
for -1?
-3?
-5?

Answer 13

1) h=-1
\(t=1.5+\displaystyle{3\over\pi}\cos^{-1}(-1/7)=?\)

Answer 14

-5=7cos(3t/pi)
2.478

Answer 15

iam getting 95

Answer 16

change your calculator to radians

Answer 17

3.13

Answer 18

3.42 for -3

Answer 19

3.75 for -5

Answer 20

are they correct

Answer 21

\[
h=-1\qquad t=1.5+\displaystyle{3\over\pi}\cos^{-1}(-1/7)=3.13s\\
h=-3\qquad t=1.5+\displaystyle{3\over\pi}\cos^{-1}(-3/7)=3.42s\\
h=-5\qquad t=1.5+\displaystyle{3\over\pi}\cos^{-1}(-5/7)=3.76s
\]
so, yes. they are correct

Answer 22

also, remember that these times can be obtained when the weight is coming from extreme to rest position and from rest to extreme. These times are from mean to extreme

Answer 23

the values you got for part (b) are from extreme to mean. to get to 1cm, it takes more time than to go to 5cm from rest position!!!

Answer 24

dont use any of my answers i solve for the equation 3/pi x not pi/3 x

Answer 25

part b's solution is wrrong

Answer 26

what are your answers for part b?

Answer 27

no. it is correct. I am giving you the interpretation. Look at the time values.

Answer 28

is it 1.36 for the first one

Answer 29

it tell you that you reach 5cm mark before you reach the 1cm mark. i.e., you are coming from the extreme point to the rest point

Answer 30

1.36,1.08,0.74 ish?

Answer 31

ok thanks can you confirm my other question

Answer 32

I do not see a series there in the picture

Answer 33

wait

Answer 34

http://prntscr.com/1229cf

Answer 35

all correct here