Calc/Trig Hybrid Homework: Find P's Height & ds/dt

[Hannelore]

Homework Statement

A mass is suspended from the ceiling on a spring. It is pulled down to point P and then released. It oscillates up and down. Its distance, s cm, from the ceiling, is modeled by the function s=48 + 10cos($$\Pi$$t) where t is the time in seconds from release.

(a)What is the distance of the point P from the ceiling. Do not use a calculator

(b) Find ds/dt

Homework Equations

The Unit Circle

The Attempt at a Solution

(a) I set it equal to zero, and then used the unit circle to find that cos($$\Pi$$) = 1, but that doesn't take into account the t.

 

[Dick]

The "point of initial release" is where t=0 isn't it? Besides cos(pi)=(-1).

Signed, Confused.

 

[Hannelore]

The "point of initial release" is where t=0 isn't it? Besides cos(pi)=(-1).

Signed, Confused.

Oh, you're right about cos(pi)=(-1)

 

[HallsofIvy]

He's also right about the mass being at point P when t= 0!