- #1
undertow2005
i'm stuck on two problems deal wih SHM
1)A mass of .5 kg is attached to a vertical spring and slowly lowered to its equilibrium position; this stretches the spring by 10 cm. Then the mass is placed below in the position whre the stretch of the spring is 15 cm, and released. calculate the distance between the highest point that the moving mass reaches and the reference level corresponding to unstrained spring.
ok, i have no clue. from the formulas that i have on SHM, i don't see how i can compute the highest point or any reference point.
2)a horizontal spring on a frictionless table has a mass 0.1 kg attached to its end. spring constant is 0.5 N/m. the spring is stretched in a way that its elongation is 10 cm and then released, so the vibration begins. find teh velocity of the attached mass at the instant of time when the elongation of spring is 5 cm. find also the maximum volocity of the mass.
i got the answer for the max velocity but not sure if its the right way to do it.
ok, Vmax=w*A, where w is angular frequency of motion and A is amplitude
so, w=2*PI*v=2PI/T=sqr(k/m
to get T, i used this equation: T=2*pi/w=2*pi*sqrt(m/k
so T=2*pi*sqrt(0.1 kg/0.5 N/m)=2.80
so w=2*pi/2.80=2.237
now, is this the correct formula to get Amplitude, a=-A*w^2
anyway, i used it, to get A=0.5 N/m/2.237^2=.100
so now i have A and w to get max velocity, Vmax=2.237*.100=.224 m/s?
i have no idea how find the velocity fo the attached mass at the instant of time when elongation of is 5 cm
now Final is tomorrow, so if you guys could show me the way to do these problems with the equations and all i'd really, really appreciate it
thanks
1)A mass of .5 kg is attached to a vertical spring and slowly lowered to its equilibrium position; this stretches the spring by 10 cm. Then the mass is placed below in the position whre the stretch of the spring is 15 cm, and released. calculate the distance between the highest point that the moving mass reaches and the reference level corresponding to unstrained spring.
ok, i have no clue. from the formulas that i have on SHM, i don't see how i can compute the highest point or any reference point.
2)a horizontal spring on a frictionless table has a mass 0.1 kg attached to its end. spring constant is 0.5 N/m. the spring is stretched in a way that its elongation is 10 cm and then released, so the vibration begins. find teh velocity of the attached mass at the instant of time when the elongation of spring is 5 cm. find also the maximum volocity of the mass.
i got the answer for the max velocity but not sure if its the right way to do it.
ok, Vmax=w*A, where w is angular frequency of motion and A is amplitude
so, w=2*PI*v=2PI/T=sqr(k/m
to get T, i used this equation: T=2*pi/w=2*pi*sqrt(m/k
so T=2*pi*sqrt(0.1 kg/0.5 N/m)=2.80
so w=2*pi/2.80=2.237
now, is this the correct formula to get Amplitude, a=-A*w^2
anyway, i used it, to get A=0.5 N/m/2.237^2=.100
so now i have A and w to get max velocity, Vmax=2.237*.100=.224 m/s?
i have no idea how find the velocity fo the attached mass at the instant of time when elongation of is 5 cm
now Final is tomorrow, so if you guys could show me the way to do these problems with the equations and all i'd really, really appreciate it
thanks