In the following diagram the bottom block is being pulled downward with a force of 15 N. Calculate the tension in rope A if the mass of the top block is 2.0 kg and the mass of the bottom block is 5.0 kg.

To calculate the tension in rope A, we need to consider the forces acting on the system.

1. First, let's consider the top block. The only force acting on it is its weight, which can be calculated using the formula: weight = mass * gravitational acceleration.

Given that the mass of the top block is 2.0 kg and the gravitational acceleration is approximately 9.8 m/s^2, we can find the weight of the top block: weight_top = 2.0 kg * 9.8 m/s^2.

2. Now, let's consider the bottom block. In addition to its weight, there is an additional force acting on it, which is the force applied to pull it downward. Given that this force is 15 N, the net force acting on the bottom block is: net_force = force_applied - weight_bottom.

The weight of the bottom block can be calculated using the same formula as before: weight_bottom = mass * gravitational acceleration, where the mass of the bottom block is 5.0 kg.

3. Once we have the net force acting on the bottom block, we can use Newton's second law of motion, which states that the net force is equal to the mass multiplied by the acceleration: net_force = mass * acceleration.

In this case, the acceleration of the system can be calculated as the acceleration of the bottom block, since the entire system moves together: acceleration = net_force / mass_bottom.

4. With the acceleration calculated, we can determine the tension in rope A by considering the forces acting on the bottom block. The tension in rope A is given by: tension_A = weight_bottom - force_applied.

By substituting the values we've already calculated, we can find the tension in rope A.