To what height h, do the combined masses swing up on the cord? A massless spring

Question

To what height h, do the combined masses swing up on the cord?

A massless spring with spring constant k is compressed by an amount xo A block of mass m is placed on the compressed spring and released from rest on a frictionless surface. This block then strikes another block of mass 2m, which is hung on a massless cord of length L as shown in the figure to the right. The masses stick together after the collision and they both swing up to a height h. Give answers for parts (a-c) in terms of k, xo. in. and or g.

Explanation / Answer

by conservation of energy (1/2) kx0^2 = (1/2) mv0^2 v = x0 sqrt(k/m) now , after collission , using conservation of momentum m*v0 = 3m*v v = v0/3 = (x0/3)*sqrt(k/m) now , again using conservation of energy (1/2) 3m*v^2 = 3m*g*h h = v^2 /2g = kx0^2 / (18mg)

Related Questions

Navigate

• Browse (All)
• Browse T
• Subjects

---

---

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