NAME______DATE______BLOCK____

Conservation of Momentum Pre-Lab
Answer the following questions with complete sentences.
(Hint: when explaining how you know these answers, you can often use the formula for momentum.)

You will start with two carts on a track. You will make them spring apart, and you will figure out the momentum of each cart after the “explosion.”

  1. The system (two carts) start out motionless. How much momentum does the system have, and how do you know?
  1. After springing apart, each cart is moving. Does each cart have momentum, and how do you know?
  1. After springing apart, is the momentum of the system the same as it was before springing apart? How do you know?

NAME______DATE______BLOCK____
Conservation of Momentum Pre-Lab
Answer the following questions with complete sentences.
(Hint: when explaining how you know these answers, you can often use the formula for momentum.)

You will start with two carts on a track. You will make them spring apart, and you will figure out the momentum of each cart after the “explosion.”

  1. The system (two carts) start out motionless. How much momentum does the system have, and how do you know?
  1. After springing apart, each cart is moving. Does each cart have momentum, and how do you know?
  1. After springing apart, is the momentum of the system the same as it was before springing apart? How do you know?

NAME______DATE______BLOCK____

Conservation of Momentum Lab

Objective: Today we are going to test the momentum of two carts as they fly apart in different directions. We will see if the momentum of the system is “conserved.” (That is, we’ll see if the momentum before the explosion (po) is equal to the momentum after (pf) they fly apart.)

Data Table (10 points)

Observe the demonstration and instructions showing how to set up the lab and take measurements.

Check your equipment to make sure your system is isolated (track is level, wheels spin freely…).

Run the lab and make measurements. Recording data accurately and precisely on the table below.

Unit / Cart 1 / Cart 2
Mass
Distance traveled / Positive: / Negative:
Time / Make at least three trials, and record the times.

When you have completed your measurements, please clean up and start your calculations.

Calculations Table (10 points)

Complete the table accurately, using the data you collected.

Unit / Cart 1 / Cart 2
Average Time
Velocity
(Is it + or –?)
Momentum
(Is it + or –?) / P1 = / P2 =
Calculate
ptotal = p1 + p2
(Is it + or –?) / (Put your result on the board.)

Answer the questions below using complete sentences.
(10 points)

  1. What object(s) are included in the system we are studying?
  1. For this lab, we assume the system is isolated. What does “isolated” mean in this case?
  1. Before taking data, what did you do to check that your system was reasonably isolated? Was there any indication that it was not isolated? If so, what?
  1. What was the momentum of your system before the explosion? How do you know?
  1. According to your data, what was the total momentum of your system after the explosion, but before hitting the barrier?
  1. Did the explosion change the momentum of the system? How do you know?
  1. Besides isolating the system, what are other error sources in this lab? (Find at least two. You may not use the phrase “human error.” Be more specific than that.)
  1. Each group calculated a total momentum. What was the average value of this total?
  1. What does it mean for momentum to be conserved during the “explosion” of the carts? According to our class results, was momentum conserved?