Question

marble going at a speed of 2 metre per second and other marble of equal mass at rest is perfectly elastic the velocity of first after collision is​

Answer 1

Answer:

0 m/s

Explanation:

From conservation of linear momentum

• m1u1 + m2u2 = m1v1 + m2v2

(m × 2) + (m × 0) = mv1 + mv2

2m = m(v1 + v2)

v1 + v2 = 2 ....(1)

From coefficient of restitution

• e = (v2 - v1)/(u1 - u2)

For perfectly elastic collision e = 1

1 = (v2 - v1)/(2 - 0)

v2 - v1 = 2 ....(2)

Add equations (1) and (2)

v1 + v2 + v2 - v1 = 2 + 2

2v2 = 4

v2 = 2 m/s

If v2 = 2 m/s then from equation (1)

v1 = v2 - 2

= 2 - 2

= 0 m/s

For a head on elastic collision of equal masses, the velocities always exchange. The velocity of projectile (u1 = 2 m/s) is exchanged by velocity of target (u2 = 0 m/s).