D:friction
Reason:because they are trying different types of things to rub against it and see if it will slow it down
Please give me the bran list answer !
System A undergoes an increase in entropy while system B undergoes a decrease in entropy.
Entropy is the degree of disorderliness of a system. The entropy of a system depends on the number of particles present in the system as well as the state of matter.
Entropy is increased when solid particles dissolve in water because more particles are produced thereby increasing the level of disorderliness in the system.
On the other hand, when vapor is condensed, the degree of disorderliness decreases as gases are converted to liquids.
Learn more: brainly.com/question/13146879
