Momentum/Impulse

Question

Two objects, A and B, initially at rest, are “exploded” apart by the release of a coiled spring that was compressed between them.

As they move apart, the velocity of object A is 5 m/s and the velocity of object B is -2 m/s. The ratio of the mass of object A to the mass of object B, m_A/m_B, is:

A. 4/25

B. 2/5

C. 1/1 (1)

D. 5/2

E. 25/4

Answer 1

mAvA + mBvB = 0 by law of conservation of momentum. Because. From here mA/mB = - v_A/v_B = 2/5.

Answer is B.