Final answer:
The acceleration a2 of the block of mass m2 in the y-direction can be expressed as a2 = (m2g - T) / m2, using the tension T and the gravitational force m2g.
Step-by-step explanation:
To write an expression for the acceleration a2 that the block of mass m2 experiences in the y-direction, we need to consider Newton's second law of motion, which states that the force acting on an object is equal to the mass of the object multiplied by its acceleration (F = ma). The only forces acting on block m2 in the vertical direction are the tension in the string (T) upward and the gravitational force (m2g) downward. Considering downward to be positive and using Newton's second law, we can express the net force on block m2 as m2g - T. This net force equals the mass of block m2 times its acceleration a2 in the y-direction. Therefore, the equation for a2 is:
m2g - T = m2 * a2
Solving for a2, we get:
a2 = (m2g - T) / m2
This expression allows us to calculate the acceleration of block m2 in terms of the tension T and the mass m2.