Trees can be a renewable source , we use them to breath , we make paper out of them , we make houses and etc.
i hope this helps
Answer:
A) If the paintball stops completely the magnitude of the change in the paintball’s momentum is 
B) If the paintball bounces off its target and afterward moves in the opposite direction with the same speed, the change in the paintball’s momentum is 
C) A paintball bouncing off your skin in the opposite direction with the same speed hurts more than a paintball exploding upon your skin because of the strength exerted is twice than if it explodes.
Explanation:
Hi
A) We use the formula of momentum 
, so we have 
B) We use the same formula above, then due we have a change of direction at the same speed, therefore the change in the momentum is the double so
.
C) The average strength of the force an object exerts during impact is determined by the amount the object’s momentum changes. therefore
, as we don't have any data about the impact time but we know momentum is twice, time does no matter and strength is twice too.
Answer:
Acid mine drainage is dissolved toxic materials wash from mines into nearby lakes and streams.
Explanation:
Acid mine drainage is the flow of acidic water with pH typically between 2 and 4, and high concentrations of other dissolved toxic materials from mines into nearby lakes and streams. It mainly occurs during metal sulfide mining, when the metal sulfide ore such as pyrite (FeS2) is exposed to water and oxygen from air to produce soluble iron and sulfuric acid.
Microorganisms, especially acidophile bacteria like Acidithiobacillus ferrooxidans grow by pyrite oxidation, i.e., oxidizing the Fe²⁺ in pyrite to Fe³⁺, which again react with pyrite and water to produce sulfuric acid. Then the acidic water flows into nearby water sources and reduces the pH value of water in those sources. As a result, heavy metals such as copper, lead, mercury, etc in other mineral ores also get dissolved into the water. The action of acidophile bacteria also increases the rate and degree of acid-mine drainage process.
The acid mine drainage causes water pollution and adversely affect the aquatic plants and animals. It also results in the contamination of drinking water, corrosion of infrastructures such as bridges, etc.
Angular momemtum : mass * tangential speed * distance to the center = 50*2.1*3.6=37800 J.s
It lasts 29 1/2 days.
-the sidereal month- is the true period of the moon's revolution around Earth. It lasts 27 1/3 days.
-the difference of 2 days between the synodic and sidereal cycles is due to the Earth- moon system also moving in an orbit around the sun.
