Question

Two pucks on a horizontal air table have attracting magnets. They are initially positioned very far from each other so that no attraction occurs. The two were given a push and collide. The pucks end up moving at 1.20 m/s, 33° above the horizontal after the collision as shown in Figure 3. Initially, the first puck with mass m₁ = 5.0 g slides with velocity 0.60 m/s due east. Find the initial velocity (magnitude and direction) of the sec ond puck (m₂ = 6.0 g)?

Answer 1

$$m_2v_{2y}=(m_1+m_2)v_y'\sin{33}\\6v_{2y}=(5+6)(1.2)\sin{33}\\ v_{2y}=1.20\frac{m}{s}$$

$$m_1v_1+m_2v_{2x}=(m_1+m_2)v_y'\cos{33}\\5(0.6)+6v_{2y}=(5+6)(1.2)\cos{33}\\ v_{2x}=1.345\frac{m}{s}$$

$$v=\sqrt{1.2^2+1.345^2}=1.80\frac{m}{s}\\\theta=\arctan{\frac{1.2}{1.345}}=41.7\degree$$