Menu div.question,div.steps {font-size: 16px; padding: 10px;line-height: 20px; margin: 20px;} div.question{border: 1px solid #ccc;} div#solution .button{font-size: 20px; margin: 20px; width: 200px; padding: 10px; text-align: center;} div.hint,div.answer,div.steps{display: none;} div.pre_next{font-size: 30px; width:90%; margin:auto;} div.pre_next a.nav_pre{float:left;} div.pre_next a.nav_next{float:right;} div.title div.notes{ font-family:sans-serif, Arial; font-size: 18px; } div.speak{display:none;} i.speak{float: right;margin-top:-10px;cursor:pointer;} 6. A 5000-kg boxcar traveling at 18.0\ m//s strikes a second 4000-kg boxcar at rest. The two cars stick together after the collision. What is the speed of the two cars after collision?6. A 5000-kg boxcar traveling at 18.0\ m//s strikes a second 4000-kg boxcar at rest. The two cars stick together after the collision. What is the speed of the two cars after collision? Hint p_i = p_f Answer v_f = 10.0\ m//s Show Steps Given: m_1 = 5000\ kg v_(1_i)=18.0\ m//s m_2= 4000\ kg Equations: p_i = p_f Solution: p_i = p_f => m_1 v_(1_i) + m_2 v_(2_i) = m_1 v_(1_f) + m_2 v_(2_f) From the given values => m_1 v_(1_i) + 0 = m_1 v_f + m_2 v_f => m_1 v_(1_i) = (m_1 + m_2) v_f v_f =m_1/(m_1 + m_2) v_(1_i) v_f =(5000\ kg) /((5000\ kg)+(4000\ kg)) (18.0\ m//s) v_f = 10.0\ m//s