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7.1 L5 Reassessment Given Friday 5/28 and 6/4

Last updated over 3 years ago
9 questions

Unit 7.1 Lesson 5 Embedded Assessment: Who Has the Bigger Increase in Splat?

Directions: Watch the Splat-o-Meter video with your classmates. Answer the questions.

The Situation:
Aniya and Joshua are learning about how the speed or mass of a moving object affects that object’s kinetic energy. To study this, they have been dropping watermelons off of ladders and off of the school roof. They’ve tried dropping watermelons from different heights (to change the speed), and they’ve tried dropping different sizes of watermelons (to change the mass). They’ve seen that with each change, the size of the watermelon “splat” changes, which shows that the kinetic energy of the watermelon has changed.


Aniya and Joshua now want to conduct an experiment.
  • Joshua decides he will change the speed (and only the speed) of the watermelons he drops.
  • Aniya decides she will change the mass (and only the mass) of the watermelons she drops.
Aniya and Joshua will then compare their results to see how each change affected the falling watermelons’ kinetic energy.

Part I: Organizing the data.

Joshua's Experiment - How does changing speed affect the splat?
Joshua collected data from dropping watermelons of the same mass from different heights and studying the amount of kinetic energy in the splat (by comparing the size of the splat). Below is her data table and graph.

3

For Joshua's experiment, identify the independent variable (the thing we change in the experiment) and identify the dependent variable (the thing affected by the independent variable). (Hint: Use Title of table as a clue.)

The independent variable is: _____________________

3

The dependent variable is: _____________________

4

Using Joshua's data table, complete a graph of Joshua's experiment. Remember to include a title and labels on both axes.

Aniya's Experiment - How does changing mass affect the splat?
Aniya collected data from dropping watermelons of different mass from the same height and studying the amount of kinetic energy in the splat. Below are her data table and graph.



Finish the following sentences to explain how mass and speed affect the amount of kinetic energy produced.
2

As the mass of an object increases, the amount of kinetic energy __________________.

2

As the speed of an object increases, the amount of kinetic energy __________________.

Part II: Analyzing the Data

3

Using Aniya's and Joshua's graphs, do either of Joshua's or Aniya's graphs contain evidence that their variables have a nonlinear relationship? Explain your thinking. (Hint: Nonlinear means not a straight line.)

Part III: Drawing Conclusions

Aniya and Joshua's teacher now asks them which change would have a bigger effect on the kinetic energy of the watermelon: doubling the mass or doubling the speed?

Joshua says if they keep the same mass but double the speed from 10 m/s to 20 m/s they’ll get a bigger increase in kinetic energy and, therefore, a bigger increase in the size of the splat.

Aniya says if they keep the same speed but double the mass from 2 kg to 4 kg they’ll get a bigger increase in kinetic energy and, therefore, a bigger increase in the size of the splat.
3

Refer back to Joshua's data from Part I. When Joshua kept the same mass but doubled the speed from 10 m/s to 20 m/s, what happened to the kinetic energy/size of splat?

3

Refer back to Aniya's data from Part I. When Aniya kept the same speed but doubled the mass from 2 kg to 4 kg, what happened to the kinetic energy/size of splat?

3

Who is right, and why? Hint: In addition to saying who has the bigger increase in kinetic energy, be sure to include by how much their kinetic energy increased. Be sure to include numerical values from the experiments as evidence for your argument.