Activities

1. Define inertia.

2. What is a force?

3. State Newton’s “first law of motion” or “the law of inertia”?

4. Describe how pushing an object in space would differ from pushing an object on earth.

5. Think about the sizes of a large rock, and a small pebble when answering the following questions:
   1. Which object would be easier to move? A large rock, or the small pebble?
   2. Once the object was moving, what would cause it to stop?
   3. Explain how the mass of the object resists change to motion.

6. Visualize yourself ice-skating, roller blading, running or biking. What happens when a very small object gets in your path, like a small pebble or dirt?  What happens when a medium size object gets in your path, like a tree root? What happens when a large object gets in your way, like another person?
   
   Relate this scenario to science. Explain how the mass of an object resists change to motion.

Answer Key/Rubric

1. Inertia is the resistance of any physical object to any change in its state of motion.
   
   
2. Acceptable responses might include, but are not limited to:

• A push or a pull

3. Every object will remain at rest or in uniform motion in a straight line unless acted on by an external force.

4. Acceptable responses may include, but are not limited to:

• In space there is no resistance acting on an object, so it would continue in a straight line forever unless it bumps into something causing it to change directions.
• On earth, you have gravity, friction, air resistance, and other objects that may get in the way or cause it to slow down

5.      a. The small pebble would be easier to move
        b. Acceptable responses might include, but are not limited to:

• the object may stop due to interference from another object, rough ground, or air resistance

c. Acceptable responses might include, but are not limited to:

• The larger the mass, the more effort it takes to get it moving. Consequently, the smaller the mass, the less effort it takes to get moving.

6. Acceptable responses might include, but are not limited to:

• If a small object got in your path, you would likely ride/move over it
• If a medium object got in you path, you would likely avoid it, hit it with little damage, or possibly get over it
• If a large object got in your way, you would likely avoid it, hit it with more damage than a medium object, or possibly be stopped completely by it.
• This scenario relates to “how the mass of an object resists change to motion” because the larger the object, the more force it takes to get it moving. The larger massed object tends to have more force than the smaller massed object.