Question

Two objects, each of mass 1.5 kg, are moving in the same straight line but in opposite directions. The velocity of each object is 2.5 ms-1 before the collision during which they stick together. What will be the velocity of the combined object after collision?

Answer 1

Answer:

Given:-

Mass (M1) = 1.5kg

Initial velocity (u1) = 2.5m/s

Mass (M2) = 1.5kg

Initial velocity (u2) = 2.5m/s

Total mass = 1.5+1.5 = 3kg

To find:-

Velocity after collision

Applying conservation of momentum before and after collision,

M1U1 - M2U2 = Mv

1.5×2.5 - 1.5×2.5 = 3v

3.75 - 3.75 = 3v

0 = 3v

v = 0m/s.

Hence the objects will have zero velocity after collision.

Answer 2

Answer:

0m/s

Explanation:

Given : m1 = m2 = 1.5kg

v1 = 2.5m/s , v2 = 2.5m/s

Let us consider that the combined velocity of that object will be v

Then applying priniciple of conservation of momentum we get ,

m1v1 + m2v2 = (m1+m2)v.

1.5x2.5 + 1.5x(-2.5) = 3v (vel. in different direc.)

0 = 3v

so , v = 0m/s