Question

free fall calculus problem help. see picture.

Answer 1

s=490t^2 represents a funtion of time yields the objects height (position) -correct?

Answer 2

yes

Answer 3

if they want to know how much time it take for the object to fall the first 160 cm . which variable do we use to to plug in this number
???

Answer 4

plug it into t?

Answer 5

t rperesents time
No

Answer 6

make equal to. 160=490t^2

Answer 7

Very Good! yes. now solve for time !

Answer 8

t=4/7. what about the second part of A?

Answer 9

what do they mean by period?

Answer 10

i think it's for the time period

Answer 11

at 4/7 seconds?

Answer 12

yes

Answer 13

or zero seconds to 4/7 seconds

Answer 14

the answer to that is 280 cm/ sec. but i don't know how to get there

Answer 15

ohh okay. so the Original function that was given represents position, if we take the derivative of the function it will give us the velocity of the object at any time 't'

Answer 16

s'(t)=980t

Answer 17

yes
that is correct

Answer 18

now plug in the time we got in part 'a'to determine the instaneious velocity

Answer 19

560

Answer 20

hmmm . that is not the answer huh?

Answer 21

or plug it into s=490(4/7)
to get 280

Answer 22

thats incorrect be cause it should be (4/7) ^ 2 - right ?

Answer 23

yeah

Answer 24

isnt average velocity an equation described as ; distance divided by the interval of time (aka period)

Answer 25

so maybe we have to integrate
. have you learned intgration

Answer 26

no i haven't

Answer 27

ok i got it !!! woohoo

Answer 28

how?

Answer 29

average distance = change in postition divided by change in time= or equivalently = (160 cm -0 cm) divided by ( 4/7 sec - 0 sec) = 280

Answer 30

sorry *average velovity - not distance

Answer 31

ohh. i got them now. thank you for your help.

Answer 32

Okay . youre welcome - I hope i helped..