A. Using a combination lens made up of lenses, each of which has a different index of refraction. Is the correct answer.
Answer:
625000 N/ m
Explanation:
m= 20 kg
v= 30 m/s
x= 12 cm
k = ?
Here when the mass when hits at spring its speed is
Vi= 30 m/s
Finally it comes to rest after compressing for 12 cm
i-e Vf = 0 m/s
Distance= S= 12 cm = 0.12 m
using
2aS= Vf2 - Vi2
==> 2a ×0.12 = o- 30 × 30
==> a = 900 ÷ 0.24 = 3750 m/sec2
Now we know;
F = ma
F= -Kx
==> ma= -kx
==> 20 × 3750 = -K × 0.12
==> k = 625000 N/ m
Yo tengo quince y soy de cali y estoy viviendo en mexico
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).
