umm.. ##m_1a## and ##m_2a## are pseudo forces because accelerating frame ##m_2## (with acceleration a towards right) is my Reference frame.
Net horizontal force on the two blocks as a system is F.
Sum of mass × horizontal acceleration of two blocks is F.
But how can you comment about their...
Attempt at Solution::
##m_2## is chosen as reference frame and FBD is drawn as shown above. We get the following equations:
From ##m_1## by choosing axes along and perpendicular to acceleration of ##m_1## w.r.t ##m_2## (##a'##):
$$
m_1 a' + m_1 a \cos{\theta} + m_1 g \sin{\theta} = N_1...