Reporting Category: Motion and Forces Standard: 2.5 - Provide and interpret examples that linear momentum is the product of mass and velocity, and is always conserved (law of conservation of momentum). Calculate the momentum of an object.

An astronaut and his space suit have a combined mass of 157 kg. The astronaut is using a 5.0 kg tool kit to repair a solar panel on the International Space Station. When the tether connecting the astronaut to the space station becomes unattached, the astronaut, still holding the tool kit, starts to float away at 0.2 m/s.

Calculate how far from the space station the astronaut will be after 1 minute. Show your calculations and include units in your answer.

Calculate the momentum of the astronaut holding the tool kit as the astronaut floats away. Show your calculations and include units in your answer.

The astronaut decides the only way to change his motion and move back toward the space station is to throw the tool kit.

Identify the direction the astronaut must throw the tool kit: toward the space station or away from it. Use the law of conservation of momentum to explain how throwing the tool kit may return the astronaut to the space station.

Calculate the velocity with which the astronaut must throw the tool kit in order to float back toward the space station at 0.1 m/s. Show your calculations and include units in your answer.

Scoring Guide and Sample Student Work Select a score point in the table below to view the sample student response.

The response demonstrates a thorough understanding of linear momentum. The response correctly calculates how far the astronaut will be from the space station after one minute and the momentum of the astronaut and tool kit. The response correctly identifies the direction the tool kit must be thrown and uses the law of conservation of momentum to clearly explain how throwing the tool kit will change the astronaut’s motion. The response also correctly calculates the velocity with which the tool kit must be thrown.