Impulse and Momentum: Guided Inquiry

Objectives:

- Measure a cart's change in momentum and compare it to the impulse it receives 

- Compare average and peak forces in impulses 

Key Terms:

- Impulse

- Momentum

- Force

- Velocity

- Average

Pre-Lab Discussion:

As discovered in the previous Momentum and Collisions Lab, we have learned that collisions are composed of a beginning, middle, and end. This lab deals with the impulse-momentum theorem, which relates and objects impulse: (force/time) to the change in momentum: (mass*change in velocity). In this lab, we will prove that an object's change in momentum is equal to its impulse. 

Procedure: 

Results:

In the following graphs, we found the force, velocity, and position (m)

Elastic 1: Beginning

Elastic 1: Middle 

Elastic 1: End 

Elastic 2: Beginning

Elastic 2: Middle

Elastic 2: End 

Data Table:

This graph measures the final velocity, initial velocity, average force, duration (s), and the calculated impulse, found by finding the average force/time. 

When we calculate the momentum of the car...

Knowing that Mass of cart = 0.51 kg.

Elastic 1: mass * velocity = (0.51 kg)(1.4957) = 0.764, which is about equal to the value we found for impulse (0.740).

Elastic 2: mass * velocity = (0.51)(2.394) = 1.223, which is about equal to the value we found for impulse (1.16).

Takeaways:

By calculating the impulse and momentum of the trials, it is simple to see how the two are equal, providing the impulse-momentum theorem. The numbers may slightly be off due to friction and/or repositioning of equipment in between trials.