Today we completed our elevator experiments by finding the acceleration of the elevator, how long the elevator accelerated for, and the distance that it traveled while accelerating. We found that the formula of _ a=F/m_ was not completely correct and changed it to
_ a=F(unbalanced)/m_. This means that if the upward force on you was 814 Newtons, and the downward force was 734 Newtons, your formula to find your acceleration would be
a=(814 N- 734 N)/ 73.4 kg
a=80 N/ 73.4 kg
a=1.09 (m/s)/s

We then discussed a few of the commonly missed questions from the test. We reviewed that, if there is no friction on the cart, than the forces are unbalanced, and therefore, if a constant force is applied, the cart constantly accelerates. Once the rope puling it breaks, there are only two forces acting on the cart which are balanced, and therefore the cart moves at a constant velocity.

Then we began talking about the force diagram for a balloon with a weight on the other end. We learned that the force pushing the balloon up is buoyancy from the air. There are two down arrows on the diagram, one for gravity and one from the tension from the string. When these forces are all balanced, then the balloon achieves equal buoyancy. If it is slightly pushed up or down, the forces are unbalanced, and it accelerates.
If the balloon, with the weight, is pushed toward the ground, the weight will touch the ground, and therefore be supported by it rather than the tension from the string. Because of this, the forces become, unbalanced, and there is less of a downward force, so the balloon accelerates upwards.
If the balloon is pushed laterally through the air, it eventually stops, because of the air resistance on the balloon.