No friction present means: Ek = Ep
So Ek = mgh = 10 * 9.8 * 2 = 196 J
The red box must way more. Gravitational potential energy is the product of a an objects mass times the acceleration due to gravity (which is constant on earth) times its height. Since the objects are on the same shelf they are at the same height, and since gravitational acceleration is constant as long as we stay on planet earth, then the mass is the only possible thing that could have changed. This means that the red box must weigh more than the blue box.
Answer:
a. 
b. 
Explanation:
I have attached an illustration of a solid disk with the respective forces applied, as stated in this question.
Forces applied to the solid disk include:
Other parameters given include:
Mass of solid disk, 
and radius of solid disk, 
a.) The formula for determining torque (
), is 
Hence the net torque produced by the two forces is given as a summation of both forces:
b.) The angular acceleration of the disk can be found thus:
using the formula for the Moment of Inertia of a solid disk;
where 
= Mass of solid disk
and 
= radius of solid disk
We then relate the torque and angular acceleration (
) with the formula:
I cant read it, i could most likely help if i could read it.
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).
