Compare collision conservation claims

Supplied materials

• All measurements and observations below are supplied classroom examples. They are not data from actual learners or a claim about a particular real site.
• Paper or a browser document for a labeled drawing, table or explanation.
• Worked problem inputs: Two isolated carts collide and stick. Total momentum remains constant but kinetic energy falls. Explain where the conservation claim applies.
• Assessment case 1: Two isolated carts collide elastically under the supplied model. What accounting applies? Which inference or prediction is best supported?
• Assessment case 2: Which scientific label fits the specifically described step or feature? Supplied case: Isolated collision converts some kinetic energy to deformation.
• Assessment case 3: Which scientific label fits the specifically described step or feature? Supplied case: Outside force acts during collision.
• Assessment case 4: Which scientific label fits the specifically described step or feature? Supplied case: One interacting cart left out of accounting.
• Assessment case 5: Which scientific label fits the specifically described step or feature? Supplied case: Isolated modeled bodies rebound without kinetic loss.
• Assessment case 6: An interacting third cart is omitted from a claimed isolated two-cart system. What follows? Which inference or prediction is best supported?

Learn the idea

In an isolated system, total momentum is conserved. Kinetic energy is conserved in an elastic collision but may transfer to other forms in inelastic collisions. These are separate conservation statements.

Elastic means momentum and kinetic energy conserved in model. Inelastic means momentum conserved but kinetic energy changes form. External impulse means surroundings change system momentum. Incomplete boundary means some interacting object or transfer omitted.

For the supplied mechanism problem, Two isolated carts collide and stick. Total momentum remains constant but kinetic energy falls. Explain where the conservation claim applies. Momentum conservation applies to the combined isolated system. Some kinetic energy transfers to deformation, thermal processes or other internal forms. Lower kinetic energy does not mean total energy is destroyed.

1. Read the supplied problem and mark the structures, processes or quantities named: Two isolated carts collide and stick. Total momentum remains constant but kinetic energy falls. Explain where the conservation claim applies.
2. Draw the relevant boundary, pathway or comparison and label it using the scientific ideas above.
3. Write a causal explanation or calculation, showing how each observation supports the result.
4. Compare your reasoning with the worked solution; name a condition that would change or limit the inference.

Check your reasoning

Your answer is temporary and is not saved to an account. Download your current answer before leaving or reloading. Written work on paper or in another app stays in your own file.

Take it further

New isolated collision changes total kinetic energy from 50 J to 35 J while momentum is conserved. Expected: 15 J transfer to other accounted forms; kinetic-energy loss does not contradict total-energy conservation.

Nothing here is saved to an account or sent to a teacher. The answer download includes your current choice and any checked feedback. It does not include choices from the separate More practice section. Download that section separately.