A piece of taffy slams into and sticks to another identical piece of taffy at rest.The momentum of the two pieces of taffy stuck together after the collision is the same as it was before the collision.Kinetic energy is a different story,for part of it turns into heat.What percentage of the kinetic energy converts into heat?

Question

Quizplus · Accepted Answer

In an inelastic collision like this, kinetic energy is not conserved and is converted into other forms of energy, such as heat or sound. Since the question asks for the percentage of kinetic energy that is converted to heat, we need to know the total amount of kinetic energy before and after the collision. Since the two pieces of taffy are identical and at rest initially, they have the same initial kinetic energy. After the collision, they are stuck together, so they move together as one object. The final kinetic energy of the two pieces of taffy stuck together is therefore less than the initial kinetic energy of the two separate pieces. Since some of the initial kinetic energy is lost and converted into heat, choice C, 50%, is the best answer.

A Piece of Taffy Slams into and Sticks to Another