- #1
mechnoid
- 11
- 0
Hey guys
If I have a cylinder of mass 5 kg and release it along the vertical axis onto a spring with stiffness coefficient (k = 1.8 kN), how would I need to set up the work/energy equation(s) to find the maximum compression and deflection of the spring. And what would the maximum velocity of the cylinder be when the cylinder is located 0.1m above the spring.
Work/energy relation
U'A-B=ΔT + ΔVg+ΔVe
Have the first part for compression calculated by
-m*g*x = m*g*0.1 - 1/2*k*x^2
-5*9.81*x = 5*9.81*0.1 - 1/2*1800x^2
Computed to give: 0.1059m (matches my answer sheet)
But I'm struggeling with how to set up a formula for the max velocity and deflection for that speed. Have tried the following for velocity
0 = 1/2*m*v^2 + m*g*compression - 1/2*k*compression^2
0 = 1/2*5v^2 + 5*9.81*0.1059 - 1/2*1800*0.1059^2
Computed velocity to be: 1.39 m/s (but this value doesn't match with the answer sheets - should be 1.493m/s)
Not sure with calculating the deflection
Thanks and keep on rocking...
If I have a cylinder of mass 5 kg and release it along the vertical axis onto a spring with stiffness coefficient (k = 1.8 kN), how would I need to set up the work/energy equation(s) to find the maximum compression and deflection of the spring. And what would the maximum velocity of the cylinder be when the cylinder is located 0.1m above the spring.
Work/energy relation
U'A-B=ΔT + ΔVg+ΔVe
ΔT = 1/2*m*v^2
ΔVg = m*g*h
ΔVe = 1/2*k*x^2
Have the first part for compression calculated by
-m*g*x = m*g*0.1 - 1/2*k*x^2
-5*9.81*x = 5*9.81*0.1 - 1/2*1800x^2
Computed to give: 0.1059m (matches my answer sheet)
But I'm struggeling with how to set up a formula for the max velocity and deflection for that speed. Have tried the following for velocity
0 = 1/2*m*v^2 + m*g*compression - 1/2*k*compression^2
0 = 1/2*5v^2 + 5*9.81*0.1059 - 1/2*1800*0.1059^2
Computed velocity to be: 1.39 m/s (but this value doesn't match with the answer sheets - should be 1.493m/s)
Not sure with calculating the deflection
Thanks and keep on rocking...