Mohon dibantu Materi fisika tumbukan

[tex]\displaystyle m_a=5\,\text{kg}\\m_b=7\,\text{kg}\\v_b=-10\,\text{m/s}\\v_a'=-5\,\text{m/s}\\v_b'=3\,\text{m/s}\\\\v_a=?\\\\m_av_a+m_bv_b=m_av_a'+m_bv_b'\\5v_a+7(-10)=5(-5)+7\cdot3\\5v_a-70=-25+21\\5v_a=-4+70\\5v_a=66\\\boxed{\boxed{v_a=13,2\,\text{m/s}}}[/tex]

Tumbukan.
Kelas X kurikulum 2013 revisi 2016.

pA + pB = pA' + pB'
mAvA + mBvB = mAvA' + mBvB'
(5 kg)vA + (7 kg)(-10 m/s) = (5 kg)(-5 m/s) + (7 kg)(3 m/s)
vA = 13,2 m/s