https://phet.colorado.edu/sims/html/forces-and-motion-basics/latest/forces-and-motion-basics_en.html Open the link above & Select Net Force.

1. Select the Values checkbox in the top right corner of the screen.
2. Decide if you want to use the blue side or the red side. You will only use one.
3. You will run three trials with different applied forces. You will adjust the amount of force by placing the characters onto the rope. Select at least one person to put on the rope.
   • Small person adds 50 N each
   • Medium person adds 100 N
   • Large person adds 150 N
4. Get your stopwatch ready to start (it might help to have someone else help to press the button for you). When ready, simultaneously press the go button on the simulator and the start button on your stopwatch.
5. Press the stop button on the stopwatch when the cart crashes into the stop block on the side. Record the amount of force used, and the time it took to reach the stop block on the lab worksheet.
6. Repeat steps 4-6 with two different amounts of force of your choosing.
7. Complete the rest of the lab worksheet.

Data CollectionTable 1:

Trial	Force used (N)	Time (s)	Distance (m) (fixed)	Acceleration (m/s2) calculate in #1 below	Mass (kg) calculate in #2 below
1			5.0
2			5.0
3			5.0

Analysis

1. Using the equation d = a t² , the value of 5.0 m for the distance (d) and the time (t) that you recorded for the wagon to reach the stop block, calculate the acceleration (a) for each trial.Show your work below. Fill in Table 1 with your answers.

Trial 1 : Trial 2 : Trial 3 :

2. Using Newton's second law of motion equation, F = m a , use the Force (F) and the acceleration (a) to calculate the mass (m) of the cart for each trial.Show your work below. Fill in Table 1 with your answers.

Trial 1 : Trial 2 : Trial 3 :

Questions

Answer questions in complete sentences.

1. Compare the accelerations for the three trials. Explain how Newton's second law was demonstrated in the simulation.

2. Describe how Newton's first and third laws would apply to this situation if this simulation was done in the real world.

3. Compare the masses that you calculated for the three trials. If the actual mass of the cart did not change (we used the same cart for all trials), what measurement do you believe contributed the largest amount of error to that calculation? Explain your answer.