Answer:
.......................
Explanation:
A net force = unbalanced force. If however, the forces are balanced (in equilibrium) and there is no net force, the object will not accelerate and the velocity will remain constant.
Henry will lift 200 N load 20 m up a ladder in 40 s. While the Ricardo will take 400 N load in 80 seconds. So, For Henry to take 400 N load it will take him 80 seconds in two attempts. And,also, he will have to cover 40 m of distance.
.Water
Adequate water supplies of high quality are necessary both for community use and local ecosystems. Communities and jurisdictions must work together to assure an adequate water supply to meet future needs. This section presents resources to aid in that effort.Energy
Communities require energy. Nonrenewable sources for power generation, home and workplace, and transportation cause pollution and its harmful impacts. Energy conservation and the use of renewable fuels provide cost-effective and more sustainable alternatives. This section contains resources available to make energy use more efficient.Air and Climate
Both the natural ecosystem and human health can be adversely impacted by declining air quality and climatic change. Communities can preserve air quality by limiting or eliminating the discharge of harmful chemicals into the air and by minimizing the sources of air pollution. This section contains resources and approaches that address air quality and climate change.Biodiversity
Biodiversity is particularly important for creating sustainability because of the specialized roles each species plays in maintaining ecological balance. Communities can promote healthy wildlife by supporting integrative approaches for managing, protecting, and enhancing wildlife populations and habitats appropriate to their area. Some examples are given here.Land, Forests, and Ecosystems
While providing a protective covering for soil, water, and the atmosphere, forests are also renewable sources of an endless variety of products. In a healthy ecosystem, policies and programs must balance economic and conservation needs. This section highlights cases where communities have developed land use practices and businesses that both conserve ecosystems and enhance local economies.
An educated guess about something. (What might happen in the future)
Answer:
The box should be placed at a distance of 
from the pivot
Explanation:
In order to be in static equilibrium, both Torques have to be the same magnitude, so:
Replacing the formula for Torque:
where X is the distance we need to find.
Solving for X we get:
As we can see, the distance does not depend on the actual value of the mass but on the fact of one being twice as much as the other one.
