Question

I don’t understand!!!

Answer 1

Answer:

A

Step-by-step explanation:

We can use momentum and conservation of momentum equation to solve this problem. The equation would be:

$m_1v_1+m_2v_2=(m_1+m_2)v_3$

m_1 is given as 2

v_1 is given as 3

m_2 is what we want

v_2 is 0 since they are sticking together after collision

v_3 is the final velocity at the resultant end, which is 1

Substituting and solving via algebra:

$m_1v_1+m_2v_2=(m_1+m_2)v_3\\(2)(3)+m_2(0)=(2+m_2)(1)\\6+0=2+m_2\\6=2+m_2\\m_2=6-2=4$

Thus, mass of 2nd box is 4kg

Answer choice A is right