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GrizzlyChicken
Group Title
The position of a mass on a spring (relative to equilibrium) at time t <= 0 is
x(t) = 2 cos((pi)t) where x is in centimeters and t is in seconds. Answer the ques
tions. Include units!
(a) What is the initial position of the mass?
(b) What is the initial velocity of the mass?
(c) What is the initial acceleration of the mass?
(d) Does the mass initially move towards the wall or away from it?
(e) At what point does the mass rst turn around?
 one year ago
 one year ago
GrizzlyChicken Group Title
The position of a mass on a spring (relative to equilibrium) at time t <= 0 is x(t) = 2 cos((pi)t) where x is in centimeters and t is in seconds. Answer the ques tions. Include units! (a) What is the initial position of the mass? (b) What is the initial velocity of the mass? (c) What is the initial acceleration of the mass? (d) Does the mass initially move towards the wall or away from it? (e) At what point does the mass rst turn around?
 one year ago
 one year ago

This Question is Closed

goformit100 Group TitleBest ResponseYou've already chosen the best response.0
post the question in physics section Not here @GrizzlyChicken
 one year ago

GrizzlyChicken Group TitleBest ResponseYou've already chosen the best response.1
its in my calc book, isn't this math?
 one year ago

nphuongsun93 Group TitleBest ResponseYou've already chosen the best response.1
a) put t = 0 and solve for x b) find x' and put t = 0 and solve for x' c) find x'' and put y = 0 and solve for x''
 one year ago

nphuongsun93 Group TitleBest ResponseYou've already chosen the best response.1
it's both physics and math lol
 one year ago

nphuongsun93 Group TitleBest ResponseYou've already chosen the best response.1
*typo fix* sorry c) find x'' and put t=0
 one year ago

GrizzlyChicken Group TitleBest ResponseYou've already chosen the best response.1
wait, its x(t)=2cos((pi)(t))
 one year ago

GrizzlyChicken Group TitleBest ResponseYou've already chosen the best response.1
sorry
 one year ago

nphuongsun93 Group TitleBest ResponseYou've already chosen the best response.1
still~ same way of solving :P
 one year ago

GrizzlyChicken Group TitleBest ResponseYou've already chosen the best response.1
damn, theres another error, i'm gonna look it all over again, for some reason copy and pasting changed everything
 one year ago

GrizzlyChicken Group TitleBest ResponseYou've already chosen the best response.1
at time t is greater or equal to 0. its right now
 one year ago

GrizzlyChicken Group TitleBest ResponseYou've already chosen the best response.1
so if i put 0 for t, its 2cos(0)
 one year ago

nphuongsun93 Group TitleBest ResponseYou've already chosen the best response.1
yup, that's the initial position
 one year ago

GrizzlyChicken Group TitleBest ResponseYou've already chosen the best response.1
is cos(0)=1?
 one year ago

GrizzlyChicken Group TitleBest ResponseYou've already chosen the best response.1
then for b) derivative of 2 is 0 so its all 0
 one year ago

GrizzlyChicken Group TitleBest ResponseYou've already chosen the best response.1
maybe
 one year ago

nphuongsun93 Group TitleBest ResponseYou've already chosen the best response.1
no no, find the derivative of the function x
 one year ago

GrizzlyChicken Group TitleBest ResponseYou've already chosen the best response.1
so the derivative of 2cos(pi*0)?
 one year ago

GrizzlyChicken Group TitleBest ResponseYou've already chosen the best response.1
which uses the product rule (0)(cos...)+(2)(sin(0))
 one year ago

GrizzlyChicken Group TitleBest ResponseYou've already chosen the best response.1
and sin(0)=0
 one year ago

GrizzlyChicken Group TitleBest ResponseYou've already chosen the best response.1
so the velocity is 0
 one year ago

nphuongsun93 Group TitleBest ResponseYou've already chosen the best response.1
wops sorry i'm here x = 2 cos (pi t) x' = 2 pi sin (pi t)
 one year ago

nphuongsun93 Group TitleBest ResponseYou've already chosen the best response.1
do you know how to derivative?
 one year ago

GrizzlyChicken Group TitleBest ResponseYou've already chosen the best response.1
yea, did you use the chain rule?
 one year ago

GrizzlyChicken Group TitleBest ResponseYou've already chosen the best response.1
is that why pi is with 2?
 one year ago

nphuongsun93 Group TitleBest ResponseYou've already chosen the best response.1
no chain rule. derivative of cos is sin. pi 's brought out when derivative.
 one year ago

nphuongsun93 Group TitleBest ResponseYou've already chosen the best response.1
dw:1349943924669:dw
 one year ago

nphuongsun93 Group TitleBest ResponseYou've already chosen the best response.1
derivative again for the acceleration equation
 one year ago

GrizzlyChicken Group TitleBest ResponseYou've already chosen the best response.1
2cos(pi*t)
 one year ago

GrizzlyChicken Group TitleBest ResponseYou've already chosen the best response.1
wait
 one year ago

GrizzlyChicken Group TitleBest ResponseYou've already chosen the best response.1
2pi*cos(pi*t)
 one year ago

nphuongsun93 Group TitleBest ResponseYou've already chosen the best response.1
almost correct, but now pi is brought one more time so it's 2 pi^2 cos (pi t)
 one year ago

GrizzlyChicken Group TitleBest ResponseYou've already chosen the best response.1
ohhh
 one year ago

nphuongsun93 Group TitleBest ResponseYou've already chosen the best response.1
x = 2 cos (pi t) x0 = 2 x' = v = 2 pi sin (pi t) v0 = 0 x'' = a = 2 pi^2 cos (pi t) a0 = 2pi^2 and idk how to do d and e
 one year ago

GrizzlyChicken Group TitleBest ResponseYou've already chosen the best response.1
does the mass move toward the wall because the acceleration is negative?
 one year ago

GrizzlyChicken Group TitleBest ResponseYou've already chosen the best response.1
oh, thats alright. you've helped me enough.Thanks!
 one year ago
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