Answer:
Group 1 - the alkali metals. The Group 1 elements in the periodic table are known as the alkali metals.
Explanation:
According to the description given in the photo, the attached figure represents the problem graphically for the Atwood machine.
To solve this problem we must apply the concept related to the conservation of energy theorem.
PART A ) For energy conservation the initial kinetic and potential energy will be the same as the final kinetic and potential energy, so



PART B) Replacing the values given as,




Therefore the speed of the masses would be 1.8486m/s
Crates is the correct answer because they create dents that make the bumps of mountains.