Choice - B is the correct one.
At the top of the arc, at one end of the swing:
-- it's not going to get any higher, so the potential energy is maximum
-- it stops moving for an instant, so the kinetic energy is zero
At the bottom of the arc, in the center of the swing:
-- it's not going to get any lower, so the potential energy is minimum
-- it's not going to move any faster, so the kinetic energy is maximum
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).
Radio waves, Middle-C, and halitosis are not forms of light.
Answer:
the magnetic field can be used to make electricity
Explanation:
Moving a magnet around a coil of wire, or moving a coil of wire around a magnet, pushes the electrons in the wire and creates an electrical current. Electricity generators essentially convert kinetic energy (the energy of motion) into electrical energy
Answer:
<em>The frequency changes by a factor of 0.27.</em>
<em></em>
Explanation:
The frequency of an object with mass m attached to a spring is given as
= 
where is the frequency
k is the spring constant of the spring
m is the mass of the substance on the spring.
If the mass of the system is increased by 14 means the new frequency becomes
= 
simplifying, we have
= 
= 
if we divide this final frequency by the original frequency, we'll have
==> ÷
==> x 
==> 1/3.742 = <em>0.27</em>
