Collision Lab

Big Questions

• What is the difference between the amount of energy lost in an elastic collision vs. an inelastic collision?
• What is a better conserved quantity-momentum or energy?

In this week's lab, we performed an elastic and an inelastic collision to see how momentum and kinetic energy would be affected. Ms. Tye changed up the purpose of the lab this time! Prior to the lab, we already knew the equation p=mv or momentum=mass x velocity. The purpose of the lab was to prove and understand why momentum is used to analyze collisions. We used two cars with a mass of 0.25 kg each for our experiment. In the elastic collision, the cars collided and bounced off each other due to the spring launchers. In the inelastic collision, the cars collided and stuck together due to velcro. We also learned about scalar and vector quantities. A scalar quantity are simple values without any certain direction (mass, temperature, energy, etc..) A vector quantity measures mass and direction (rightward [+] and leftward [-]) We collected our data on the Vernier program. The dips/ hill represents the car's change in velocity

Here is a chart of both collisions involving velocity, momentum, and kinetic energy.

We also had to find the percent difference for the amount of energy and momentum that entered or left the system.

(total energy after-total energy before/average of total energy before and after) x100

Inelastic Collision

Elastic Collision

• also used for momentum!

We could see that almost all of the energy was lost in the system based on the percent errors. Most of the time, momentum was conserved. Therefore, momentum is better conserved in a collision. Energy is lost due to many factors in a system.

Real Life Connection-Golf!
 When playing golf, the club collides with the tiny golf ball. This is an example of an elastic collision. ENergy is transferred from the club to the ball. We must also remember that energy is lost to many factors in a system and momentum is better conserved.