Question

see the attached file this is the question of class 9 NCERT book physics question force and law of motion give me the answer fast otherwise wrong answer will be reported and maybe their account banned so Spammer keep away​

Answer 1

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 m/s before collision during which they stick together. What will be the velocity of the combined objects after collision ?

Answer :

Given :

• Mass of first object (m₁) = 1.5 kg
• Velocity of first object (v₁) = 2.5 m/s
• Mass of second object (m₂) = 1.5 kg
• Velocity of second object (v₂) = -2.5 m/s (In opposite direction)

To find :

• Velocity of the combined objects after collision.

According to the question,

→ Momentum of first object = m₁ × v₁

→ Momentum of first object = 1.5 × 2.5

→ Momentum of first object = 3.75 kg m/s

Now,

→ Momentum of second object = m₂ × v₂

→ Momentum of second object = 1.5 × (-2.5)

→ Momentum of second object = -3.75 kg

→ Total momentum before collision = 3.75 + (-3.75)

→ Total momentum before collision = 3.75 - 3.75

→ Total momentum before collision = 0 kg m/s

So,

→ Total mass = m₁ + m₂

→ Total mass = 1.5 + 1.5

→ Total mass = 3.0 kg

→ Total momentum after collision = (m₁ + m₂) × v

→ Total momentum after collision = 3.0 × v

Now,according to the principle of conservation of momentum :

→ Total momentum before collision = Total momentum after collision during

→ 0 = 3.0 × v

→ 0 ÷ 3.0 = v

→ 0 = v

Thus,the velocity of the combined objects after collision will be zero meters per second square which means that the combined objects will come to a stop after the collision.

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