Answer:
164.87 J
Explanation:
From the question,
Work done (W) = mghcosθ........................ Equation 1
Where m = mass of the box, h = height, g = acceleration due to gravity, θ = angle to the vertical
Given: m = 25 kg, h = 2.6 meters, θ = 75°.
Constant: g = 9.8 m/s²
Substitute these value into equation 1
W = 25×9.8×2.6×cos75°
W = 164.87 J.
The correct answer is A. Acid rain forms from human activities and lowers the pH of rainwater below 7
Explanation:
The term "acid rain" is used to refer to rainwater with a low pH or a high acidity, this includes rainwater with a pH below 7 (solutions with a pH under 7 are acidic). In terms of formation, acid rain is mainly the result of human activities such as factories or cars that release pollutants into the atmosphere including nitric and sulfuric acids and these alter the natural pH of rain and makes it more acidic. Additionally, acid rain has negative consequences such as the death of fishes and other organisms in lakes, rivers, etc. because the acidity is toxic to many organisms. Thus, acid rain is the result of human activities and it lowers the pH of rain (Option A).
Newton’s first law states that if a body is at rest or moving at a constant speed in a straight line, it will remain at rest or keep moving in a straight line at constant speed unless it is acted upon by a force.
Newton’s second law is a quantitative description of the changes that a force can produce on the motion of a body. It states that the time rate of change of the momentum of a body is equal in both magnitude and direction to the force imposed on it.
Newton’s third law states that when two bodies interact, they apply forces to one another that are equal in magnitude and opposite in direction. The third law is also known as the law of action and reaction. This law is important in analyzing problems of static equilibrium, where all forces are balanced, but it also applies to bodies in uniform or accelerated motion.
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The first law represented in the game would be the candy. If you blow it, it would move but then stop due to friction.
The second law would be represented by blowing the candy. Since the candy was light, it would be easier to blow but if it was heavier, it would be a lot harder.
The final law represented in the game would be if you decided to blow the candy with a ballon instead, the candy would move the opposite direction the ballon is moving.
