# Simple Harmonic Motion

_{}b]1. Homework Statement [/b)

The position of a 39.8 g oscillating mass is given by the equation x(t)= (2.00cm)cos(5t- 4.00$$\pi$$) where t is in seconds. Determine Velocity at t= 0.250s

M= 39.8 g
K= 9.95e-1 N/m
initial postion= 2 cm

## Homework Equations

V$$_{x}$$= -$$\omega$$Asin($$\omega$$t + $$\phi$$)

## The Attempt at a Solution

the attempt i just substitued
V$$_{x}$$= -5 rad/s*2sin( 5.00(0.250)-4$$\pi$$).... but this didn't work and i dont understand why???

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for the the equations posted its supposed to be V subscript x= wAsin(wt + phi) and x(t) = (2.00cm)cos(5t - 4pi)

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Homework Helper
The position of a 39.8 g oscillating mass is given by the equation x(t)= (2.00cm)cos(5t- 4.00$$\pi$$) where t is in seconds. Determine Velocity at t= 0.250s
What is the basic relation connecting velocity and position of any particle? Use that.

_{}b]1. Homework Statement [/b)

The position of a 39.8 g oscillating mass is given by the equation x(t)= (2.00cm)cos(5t- 4.00$$\pi$$) where t is in seconds. Determine Velocity at t= 0.250s

M= 39.8 g
K= 9.95e-1 N/m
initial postion= 2 cm

## Homework Equations

V$$_{x}$$= -$$\omega$$Asin($$\omega$$t + $$\phi$$)

## The Attempt at a Solution

the attempt i just substitued
V$$_{x}$$= -5 rad/s*2sin( 5.00(0.250)-4$$\pi$$).... but this didn't work and i dont understand why???
it seems work to me...

Your right it does work, i guess I entered in the wrong units when i answered the question( m/s instead of cm/s).