Final answer:
The probability that a randomly chosen string is attached above the 30 cm mark on a uniformly distributed mass meterstick hanging from two strings, with one at the 25 cm mark, is 14/15.
Step-by-step explanation:
The question involves understanding the concept of probability and applying it to a physical situation involving a uniformly distributed mass in a meterstick. If a meterstick with a uniformly distributed mass hangs from two short strings and one is located at the 25 cm mark, the rest of the meterstick from 25 cm to 100 cm is where the second string can possibly be attached. Given that the total length of the meterstick is 100 cm, the section above the 30 cm mark would be from 30 cm to 100 cm, which is a length of 70 cm.
Considering that any point along this length is equally likely to be chosen due to the uniform distribution of mass, the probability that the randomly chosen string is attached to a point above the 30 cm mark is the length above the 30 cm mark (70 cm) divided by the total length where the string can be attached (75 cm from the 25 cm mark to the end). This gives a probability of 70/75 or equivalently, 14/15.