If the wing stalls and the upward force decreases to 2.16 kN, what is the acceleration of the sailplane (enter first)? Is it upward or downward?

To answer this question, we need more information such as the mass of the sailplane. However, I can guide you on how to calculate it once you have the necessary data.

1. Convert the force from kN to Newtons by multiplying by 1000. So, 2.16 kN becomes 2160 N.

2. Use Newton's second law of motion, which states that Force = mass * acceleration. You can rearrange this formula to solve for acceleration: Acceleration = Force / mass.

3. Plug the force (2160 N) and the mass (in kg) of the sailplane into the formula to find the acceleration.

4. If the acceleration is positive, the sailplane is accelerating upwards. If the acceleration is negative, the sailplane is accelerating downwards.

Remember, this is a simplified explanation. In reality, you'd also have to consider other forces acting on the sailplane, like gravity and drag.