Im sure this is very easy but just learning

V=velocity

A=acceleration

S=displacement

t=time

if V=4t+5 and S=10m when t=1s, find S when t=2s

just not sure what to do :/

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- Feb 16th 2009, 05:32 AMdjmccabieKinematics
Im sure this is very easy but just learning

V=velocity

A=acceleration

S=displacement

t=time

if V=4t+5 and S=10m when t=1s, find S when t=2s

just not sure what to do :/ - Feb 16th 2009, 06:41 AMADARSH
- Feb 16th 2009, 07:27 AMdjmccabie
so by integrating i get 2t^2 + 5t ???

and does this = s/t?

still a bit uncertain thankyou for helping - Feb 16th 2009, 07:40 AMADARSH
**1**

$\displaystyle

\frac{ds}{dt}= 4t+5

$

**2**

$\displaystyle

ds=(4t+5)dt

$

**3**

$\displaystyle

\int{ds} =\int{4t+5}dt

$

**4**

$\displaystyle

s=\frac{4t^2}{2} + 5t +c

$

**5**

Now at t=1s

s= 2 + 5 +c = 10m

hence c= 3

**6**

Put the value of t= 2s

s= 18+3 =21m

(Nod)

Now tell the step(s) that you dont get or have a doubt in(Smirk) - Feb 16th 2009, 07:55 AMdjmccabie
thing is i've never really been taught what the '+C' part is just told to write it (which i forgot to do lol) but yes i understand your method thanks