The spring with spring constant k = 300 N/m is connected to the floor and to a 9

Question

The spring with spring constant k = 300 N/m is connected to the floor and to a 90 kg collar A.  Collar A is at rest, supported by the spring, when the 135 kg box B is released from the position shown.  What are the velocities of A and B when B has fallen 1meter?

The spring with spring constant k = 300N/m is connected to floor and to a 90kg collar^. Collar A is at rest, supported by the spring, when the 135kg box B is released from the position shown. What are the velocities of A and B when B has fallen 1m?

Explanation / Answer

when block b decends by 1 m,

conserving the energy of the system,

135*9.8*1 = 1/2*135*vb^2 + 1/2*90*va^2 +1/2 *300 *xa^2

note that ,

xa = 3- [(sqrt13-1)^2- 4)]^1/2 = 1.33 m

also,

at that time ,

va =Vb cos theta ...............(cos theta = 2/(sqrt13-1)

Va = 0.7676 Vb

putting all this in equation

135*9.8*1 = 1/2*135*vb^2 + 1/2*90*(0.76vb)^2 +1/2 *300 *1.33^2

solving this, vb = 3.36m/s

and va = 2.556 m/s

Related Questions

Navigate

• Browse (All)
• Browse T
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.