Question

a 62.0 kg curler runs into a stationary 78.1 kg curler and they hold on to each other. Together they move away at 1.29 m/s, west. What was the original velocity of the 62.0 kg curler?

Answer 1

Momentum P is given by:
$P = mv$

Given: m₁ = 62 kg, m₂ = 78.1 kg, v₁ = ?, v₂ = 0 m/s, v₁₊₂ = 1.29 m/s

before:
$P = m_1 v_1 * m_2 v_2 = m_1 v_1$

after:
$P = (m_1 + m_2)v_{1+2}$

Since momentum is conserved, the momentum before the collision must be equal to the momentum after the collision.

$P = m_1 v_1 = (m_1 + m_2)v_{1+2} \\ v_1 = \frac{(m_1 + m_2)v_{1+2}}{m_1}$

Solve for v₁.