Question

Two blocks have mass m and M = 4.44 m, re-

spectively. A light spring is attached to one
of them, and the blocks are pushed together,
compressing the spring between them. They
are secured, in this compressed state, by a
cord. They are then placed, at rest, on a hor-
izontal, frictionless surface. The cord holding
them together is burned, after which the block
of mass M moves to the right with a speed of
2.71 m/s.
What is the speed of the block of mass m?
Answer in units of m/s.

Answer 1

12.03 m/s

Step-by-step explanation:

We can solve this by using the law of conservation of energy

ΔE=0

`mv_(i1) + Mv_(i2) = mv_(f1) + Mv_(f2)`
(Initially both blocks are compressed and at rest)

Solve for
`v_(f1)`

`v_(f1) = (mv_(i1) + Mv_(i2)-Mv_(f2))/(m)= (0+0+(-4.44m(2.71)))/(m) = 12.03 m/s`