Look for: If the force of gravity between the two objec…

14.B Use a simulation of a two-object system to produce data that can be analyzed to identify patterns to determine how changes in the mass or distance between the objects in the system affects the strength of gravitational forces between those objects in space.

Look for students to identify the following relationships:

• If the force of gravity between the two objects decreases (mass decreases or distance between objects increases) or the outer object moves faster, the outer object will fly away.
• If the force of gravity between the two objects increases (mass increases or distance between objects decreases) or the outer object moves too slowly, the outer object will crash into the inner object.

With reference to the computer interactive, ask students to show you what they can manipulate in the system. Ask them what was interesting about their object or why they chose it to be represented in the interactive. Ask students what each object and component represents in the system. Reinforce that these manipulations are not possible in the real world . Use hypotheticals (“What if the Moon …”) to help students link simulation results to the actual orbit of the Moon or another object of their choosing. If students are still struggling to identify the independent and dependent variables, ask them to tell you what they changed in the system and what the effect was on their objects. If students need additional probing to identify independent and dependent variables, ask them what they kept constant or did not change in the system.

In the last 3 minutes available, have students close the interactive and discuss with their small group the making-sense questions on Simulating a Two-Object System.