Question

The position of an object at time t is given by s(t) = -9 - 5t. Find the instantaneous velocity at t = 4 by finding the derivative.

Answer 1

\[{ds(t) \over dt} = v(t) = { d\over dt}(-9 - 5t)\]
\[{d \over dt} (-9) = ??\]
\[{d \over dt} (-5t) = ??\]

Answer 2

what? sorry that is confusing me

Answer 3

ok

you are asked to find the derivative of: \(s(t) = -9 - 5t\)

that will give you an equation for the velocity \(v(t)\) of the object.

how do you propose to do that?

Answer 4

v (t) = ds/dt?

Answer 5

That is correct. The velocity is the derivative of the position function.

Answer 6

If you plug in a specific time into the velocity function you find the INSTANTANEOUS SPEED.

Answer 7

So if i put v (9) = ds/d(9)

Answer 8

i mean 4

Answer 9

i strongly suggest you do the derivative first. then you will see :p

Answer 10

Yeah see the problem is I dont know how to do any of this, like for this lesson i missed it in school, and im doing a review right now for the quiz tomorrow and i dont understand this at all

Answer 11

@IrishBoy123, Yes that would make your night much easier. By taking the derivative of the position function you get the velocity function. But in this case its not much of a velocity FUNCTION then it is a velocity CONSTANT.

Answer 12

sO IT WOULD BE a velocity constant? whats that

Answer 13

@Loser66 @satellite73

Answer 14

Yes, But if you take the derivative of the position function, what do you get?

Answer 15

idk? how would i find that