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Common Assessment- Motion and Stability: Forces and Interaction

Last updated over 3 years ago
17 questions
Motion and Stability: Forces and Interaction
MS-PS2-2: Plan an investigation to provide evidence that the change in an object’s motion depends on the sum of the forces on the object and the mass of the object.
Background
Andy, a student at Franklin HS, is driving home from school along Powell Blvd at 36 mph (16 meters per second). It’s a route he takes often and his mind starts to wander. Suddenly, he realizes the light he is approaching is red. He slams on the brakes and skids to a stop right before the intersection.
1

Why does the car skid to a stop when brakes are applied, instead of stopping right away? Explain in terms of the forces involved.

1

Forces at Work - The following visuals show a car at different stages of motion.
  1. Draw a force diagram for the car for the two scenarios that are given in the diagram.
  2. Be sure to include all forces acting in this system at that time by using arrows, as shown in the “Before Braking” example.
  3. Draw the motion of the car during braking and at a complete stop. The length of the arrow will represent the relative speed of the car in that direction.
  4. Determine whether the forces acting on the car are balanced or unbalanced.

Performance Task: Planning and Carrying out an Investigation

The next day Andy chatted with his friend, Maile, about the accident he might have caused. He said, “I’m glad my car has good brakes.”

Maile responded, “You drive a small car. I wonder what would have happened if you drove a truck. My uncle drives a big truck for the company he works at, and he says he really has to pay attention because the truck doesn’t respond quickly.”

Andy and Maile were curious to learn more about how various cars drive differently. They got some friends together and decided to run an experiment (for extra credit in their physics class).

Andy and Maile decided to investigate the following question:
  • “How does the mass of a car affect the distance it takes for the car to stop after the brakes are applied?”
1

Write a claim that explains the relationship between the mass of a car and the distance it takes for the car to stop.

Here is a sentence frame that you can use.
  • The ______the mass of the car is the _______it will take for the car to stop when_________.

1

Justify your claim using at least one piece of evidence from classroom activities or from personal experience.

Here are some sentence frames that you can use.
  • I have observed that_____________.
  • This evidence shows that ________.
  • The evidence supports the claim by ________.

Designing an Investigation
You are going to design an investigaiton to answer the question: How does the mass of a car affect its change in motion once the brakes are applied?

Following are variables that can be manipulated within this investigation. For each variable determine if it is a(n):
  • independent variable
  • dependent variable
  • control variable
1

For the investigation " How does the mass of a car affect its change in motion once the brakes are applied?"
Is the variable "Car Mass" a(n)

1

For the investigation " How does the mass of a car affect its change in motion once the brakes are applied?"
Is the variable "Car speed before braking" a(n)

1

For the investigation " How does the mass of a car affect its change in motion once the brakes are applied?"
Is the variable "Road condition/friction" a(n)

1

For the investigation " How does the mass of a car affect its change in motion once the brakes are applied?"
Is the variable "Stopping Distance" a(n)

1

For the investigation " How does the mass of a car affect its change in motion once the brakes are applied?"
Is the variable "Slope of the ground surface" a(n)

1

Think about how Andy and Maile should set up their investigation so they can test the relationship between the independent and dependent variables.

Explain below how they will keep the control variables, that you identified above, the same throughout the investigation.
  • Example - All cars will have the same tires.

1

Explain below how you will measure the dependent variable.

The tool(s) I will use to measure _________(dependent variable)_________ is/are ____________________

1

The unit that Andy and Maile should use to measure _____________(dependent variable)__________ is________

1

Explain how you will change the independent variable, including the number of variations you will test and some values you would use that would provide useful data.

1

Draw and label the experimental setup that Andy and Maile could use to collect data.

Be sure to include and label the:
  • Independent variable
  • Dependent variable
  • Control variables

Evidence
The following graphs show data collected from four different groups who conducted similar investigations to the one Andy and Maile designed.
1

Which results best support the hypothesis you made in Question 3?

1

Explain why this group’s data supports your hypothesis better than the other three graphs.

Sentence frames that you can use:
  • The data table/graph shows ______________.
  • According to the graph, when ________ was __________then _______ happened.

1

Highly Proficient:
The relationship between mass and change in motion is represented in the following formula: F = ma
  • F = Force
  • m = mass
  • a = acceleration (change in motion)
Use this formula as evidence to support or refute the claim you made in your hypothesis.