Collisions Lab

Purpose:
In this lab we focused on the differences between what an elastic and inelastic collision is. As a result we learned which is better conserved, momentum or energy. To find out whether momentum or energy is better conserved and see the differences between inelastic and elastic collisions, we tested both collisions. We took two cars, a ramp, and a labquest machine to record the velocity of one of the cars as it moves to create a collision with the other car. From there we record the momentum and kinetic energy of each car and the total.
                     

Key Information:

 Before performing these collisions we learned a couple terms that may help us in understanding momentum. Vectors and scalars both deal with magnitude but vectors also have direction. In the first collision we performed an example of an elastic collision, which is when objects collide and bounce off. The second collision we performed was the inelastic collision, which is when objects collide and stick together. To calculate the momentum we use the equation P=mv. P stands for momentum, m stands for mass and v stands for the velocity. To find the kinetic energy we use K= 1/2mv^2.

                      Elastic Collision:

                      Inelastic Collision:

Key Conclusions:

 As a result we learned that momentum is better conserved because the momentum total before is equal to the momentum total after. In other words, it is better conserved because when one cart is moving to the right(positive) and the other is moving to the left(negative) they cancel out which makes the momentum 0 or better conserved. This connects to why direction is important for vectors. In solving for kinetic energy the positives and negative might not always cancel out, so we have to make sure we know the direction an object is moving when dealing with the kinetic energy in collisions.

Real Life Connection:

An example of an inelastic or elastic collision would be car accidents. When a cars gets into an accident sometimes one bounces off from the other or they either stick together. When one car "bounces off" from the other car its momentum continues on into the other car, causing it to move a little more after it has been hit.