Calculate Time for Mass to Reach Equilibrium Position

AI Thread Summary
The discussion centers on calculating the time required for a mass of 0.2 g, hanging from a spring with an elastic constant of 20 N/m, to return to its equilibrium position after being pulled down 0.1 m and released. The initial calculation provided was T = 0.628 seconds, which represents the period of one complete oscillation. However, it was clarified that the time to reach the equilibrium position is actually one-fourth of the total period, leading to a corrected time of 0.157 seconds. This adjustment accounts for the mass moving from the lowest point back to the equilibrium position. The final consensus is that the correct time for the load to reach equilibrium is 0.157 seconds.
timtng
Messages
25
Reaction score
0
A load of mass .2 g is hanging from a light spring whose elastic constant is 20 N/m. The load is pulled down .1 m from its equilibrium position and released.

How long is required for the load to reach its equilibrium position?

T=2pi(square root(m/k))=.628s

Please verify to see if I did it correctly.

Thanks
 
Physics news on Phys.org
I'm not looking carefully, but you seem to be wrong. It asks the time taken to reach the initial equilibrium position, while you seem to have given the periodic time for an oscillation in SHM, which would be 4*t.
 
so the answer should be T/4?
 
Yes. The "T" you give is the time to go up to the maximum height, then back down to the initial position: 1 cycle. The weight will take exactly 1/4 of that time to go back to the equilibrium point (1/2 T to reach the highest point, 3/4 T to pass the equilibrim point again and then at T back to the initial point).
 
so t should equal to .628s/4 = .157 s
 
Thread 'Variable mass system : water sprayed into a moving container'
Starting with the mass considerations #m(t)# is mass of water #M_{c}# mass of container and #M(t)# mass of total system $$M(t) = M_{C} + m(t)$$ $$\Rightarrow \frac{dM(t)}{dt} = \frac{dm(t)}{dt}$$ $$P_i = Mv + u \, dm$$ $$P_f = (M + dm)(v + dv)$$ $$\Delta P = M \, dv + (v - u) \, dm$$ $$F = \frac{dP}{dt} = M \frac{dv}{dt} + (v - u) \frac{dm}{dt}$$ $$F = u \frac{dm}{dt} = \rho A u^2$$ from conservation of momentum , the cannon recoils with the same force which it applies. $$\quad \frac{dm}{dt}...
TL;DR Summary: I came across this question from a Sri Lankan A-level textbook. Question - An ice cube with a length of 10 cm is immersed in water at 0 °C. An observer observes the ice cube from the water, and it seems to be 7.75 cm long. If the refractive index of water is 4/3, find the height of the ice cube immersed in the water. I could not understand how the apparent height of the ice cube in the water depends on the height of the ice cube immersed in the water. Does anyone have an...
Back
Top