Question

A Big fish eats a little fish. The large 45.0 kg fish is moving at a velocity of
10.0 m/s when it swallows a 5.0 kg fish at rest. How fast will the two fish be
going after the collision?​

Answer 1

GiveN :-

• A Big fish eats a little fish. The large 45.0 kg fish is moving at a velocity of 10.0 m/s when it swallows a 5.0 kg fish at rest.

To FinD :-

• How fast will the two fish be going after the ccollision .

SolutioN :-

Given that a Big fish eats a little fish. The large 45.0 kg fish is moving at a velocity of 10.0 m/s when it swallows a 5.0 kg fish at rest.We need to find how fast will the two fish be going after the ccollision . We can use the law of conservation of momentum according to which in a system the Total momentum remains conserved .

★Using the Law of Conservation of Momentum:-

$\sf\dashrightarrow \pink{ m_1u_1+m_2u_2= m_1 v_1+m_2v_2 }\\\\\sf\dashrightarrow m_1u_1+m_2u_2 = v ( m_1+m_2) \\\\\sf\dashrightarrow (45 kg)(10m/s)+(5 kg)(0m/s)= v(45+5) \\\\\sf\dashrightarrow 450 kg-m/s + 0 = (50kg)v \\\\\sf\dashrightarrow v(50kg) = 450 kg-m/s \\\\\sf\dashrightarrow v =\dfrac{450 kg-m/s}{50kg} \\\\\sf\dashrightarrow \underset{\blue{\sf Required\ Velocity }}{\underbrace{\boxed{\pink{\frak{ Velocity_{(combined)} = 9m/s}}}}}$