Name: ______________________________ Balloonist Drops Lemonade – Online Simulation Go to https://goo.gl/Y2bkGa Open and run the simulation. A balloonist is holding a large cup of lemonade (the yellow ball) so that it extends just outside the balloon's basket. The balloon is rising at a constant speed of 10m/s. At time 0.00s, when the lemonade is 15.0m above a crew member's head, the balloonist accidentally releases the lemonade. Determine the time when the lemonade reaches the head of the crew member. Assume the gravitational constant is 10.0m/s2. To solve the problem, complete the following descriptions of the problem and answer the questions. 1. Pictorial Description: Construct a pictorial description of the process, including 

a rough sketch that shows the cup of lemonade at the instant it is released and just before it hits the crew member's head



a coordinate axis with an origin at the crew member's head and the positive direction up



symbols for the initial and final values of the kinematic quantities, and the known values of any of these quantities

When you are finished, open and run the simulation to check your work.

2. Why is the acceleration zero before release, even though the cup is moving up?

Name: ______________________________ Balloonist Drops Lemonade – Online Simulation 3. Immediately after the balloonist releases the cup of lemonade, the acceleration changes from 0.0 to -10.0m/s2. The cup continues moving upward. Why? When you are finished, compare your thinking with that of the Advisor.

4. Motion Diagram: Construct a motion diagram for the cup before and after its release. To prevent overlap of upward and downward parts of the diagram, displace the dots and arrows for the downward-moving cup to the right side of the dots and arrows for the upward-moving cup. What is the cup's acceleration at the highest point? When you are finished, open and run the simulation to check your work.

5. Graphs: Kinematics graphs represent the changing position, velocity, and acceleration of an object as a function of time. Construct position-versus-time, velocity-versus-time, and acceleration-versustime graphs for the cup's motion. For an extra challenge, include both the times before and after the release of the cup. When you are finished, open and run the simulation to check your work. 𝑦

𝑣𝑦

𝑎𝑦

Name: ______________________________ Balloonist Drops Lemonade – Online Simulation 5. Continued. Move the slider below the simulation and answer the following questions. a) Why is the red velocity line initially level and positive?

b) Why does the red velocity line tilt down when the cup is released?

c) What is the status of the cup when the red velocity line crosses the time axis?

d) After the red velocity line crosses the time axis, its value is increasingly negative. Why?

e) When the cup is at its highest point, what is the value of the velocity?

f) When the cup is at its highest point, what is the value of the acceleration? Note the slope of the velocity-versus-time graph at that time

6. Equations: Substitute the values of acceleration, the initial position, and the initial velocity into the 1

equations of motion. 𝑣𝑓 = 𝑣0 + 𝑎𝑡 and 𝑦𝑓 = 𝑦0 + 𝑣0 𝑡 + 2 𝑎𝑡 2 Solve for the time when the cup reaches the crew member's head. The clock starts when the cup is released. You will need to solve a quadratic equation. Open and run the simulation.

7. What does the negative solution (t = -1.0s) to this quadratic equation mean?