Question

You will be colliding two carts in this lab. Select all the systems for which you predict the total momentum of the system will be approximately constant before, during, and after the collision
a. The system of the cart that is initially stationary
b. The system of the cart that is initially moving
c. The system of both carts
d. None of the systems

Answer 1

From the momentum conservation we know that the initial momentum is equal to the final momentum. The momentum in a singular way can be defined as the product between the mass and the velocity of an object. In the presented system, however, there are two objects, therefore the mass of both and the speed of both, before and after the collision must be taken into account. Mathematically we could describe this as

$m_1u_1+m_2u_2 = m_1v_1+m_2v_2$

Here,

$m_{1,2}$ = Mass of each object

$u_{1,2}$ = Initial velocity of each object

$v_{1,2}$ = Final velocity of each object

From here we can realize that it is necessary to use the system on both cars to be able to predict what will happen either with their masses, or their speeds.

The correct answer is C.