Question

A 3.60-kg object is moving toward the right at 6.50 m/s. A 5.00-kg object moves to the left at 4.00 m/s. After the two objects collide completely elastically, the 3.60-kg object moves toward the left at 5.70 m/s. 1) What is the final velocity of the 5.00-kg object

Answer 1

Answer:

v₂ = -3.42 m/s

Explanation:

Given that,

Mass of an object, m₁ = 3.6 kg

Initial speed of this object is, u₁ = +6.5 m/s (positive for right)

Mass of another object, m₂ = 5 kg

Initial velocity of this object, u₂ = -4 m/s (negative for left)

Fina velocity of object 1, v₁ = 5.7 m/s

We need to find the final velocity of object 2 i.e. 5 kg object.

It is a concept based on the conservation of momentum. Using the conservation of momentum as follows :

$m_1u_1+m_2u_2=m_1v_1+m_2v_2$

v₂ is the final velocity of 5 kg object.

Putting all the values to find it.

$v_2=\dfrac{m_1u_1+m_2u_2-m_1v_1}{m_2}\\\\v_2=\dfrac{3.6(6.5)+5(-4)-3.6(5.7)}{5}\\\\v_2=-3.42\ m/s$

So, the final velocity of the object 2 is 3.42 m/s and it is towards left.