Question

The position of an object at time t is given by s(t) = -9 - 3t. Find the instantaneous velocity at t = 8 by finding the derivative.
@ganeshie8

Answer 1

do you know how to calculate velocity from the time dependent equation of position ?

Answer 2

\[\large \text{velocity} = \text{(position)}'\]

Answer 3

differentiate s(t) to get the velocity

Answer 4

\[ \large \begin{align} \\

s(t) &= -9-3t \\
v(t) &= s'(t) = ?\\


\end{align}
\]

Answer 5

i dont understand that at all... @ganeshie8

Answer 6

differentiate s(t),
what do u get ?

Answer 7

\[ \large \begin{align} \\

s(t) &= -9-3t \\
v(t) &= s'(t) = (-9-3t)'\\
&=0-3\\
&=-3\\
\end{align}
\]

right?

Answer 8

oh i think i understand it now that it is written out! thanks!

Answer 9

good, basically in this problem, velocity doesnt depend on time
the object is goign at constant velcity of -3 m/s or whatever units

Answer 10

so at t=8 also, the velocity would be -3