The Block–Spring System Revisited

[adashiu]

Please help me to solve this verz simple problem :

A 0.500-kg mass attached to a spring with a force constant
of 8.00 N/m vibrates in simple harmonic motion
with an amplitude of 10.0 cm. Calculate (a) the maximum
value of its speed and acceleration, (b) the speed
and acceleration when the mass is 6.00 cm from the
equilibrium position, and (c) the time it takes the mass
to move from to x=0 to x= 8 cm.

Thanks, Adam

 

[rock.freak667]

First you need to post what you've attempted.

Try writing down the equation for simple harmonic motion for a spring.

 

[adashiu]

I have done point a )

b)
I need to have time t.
x=6cm
$$\omega$$=$$\sqrt{\frac{8}{5}}$$
6cm=10cm*sin($$\omega$$*t)

sin($$\omega$$*t) = 0,6
t=~30

Which is not correct... I think... Why? I don't know :(

 

[Doc Al]

Recalculate ω. The mass is 0.5, not 5. Be sure to measure the angle in radians, not degrees.

 

[adashiu]

Oh yes ;] You are right. Thanks guys :)