Draw a free-body diagram for block B and explain Newton's Second Law.

2.1

Newton's Second Law of Motion states that the net force acting on an object is directly proportional to the object's mass and its acceleration, and the acceleration is in the direction of the net force. Mathematically, this is expressed as $\vec{F}_{net} = m\vec{a}$.

2.2

Here is the labelled free-body diagram for block B:

      ^ Normal Force (N_B)
      |
      |
      +------- Applied Force (F_app = 32 N)
      |       (to the right)
      |
      v Gravitational Force (F_gB = m_B g)
      <------- Tension