Answer: (1) The correct answer is A.
(2) The correct answer is D.
Explanation:
(1)
Reflection is the sending back of light from the surface without absorbing it. In the reflection phenomenon, the wave does not continue moving forward.
Diffraction is the bending of the light around the obstacle. In the diffraction phenomenon, the wave travels forward after striking around the obstacle.
Therefore, the correct answer is A.
(2)
Amplitude is the maximum displacement in the medium from the rest position.
The amount of energy is related to the amplitude. Amplitude is related to the amount of energy carried by the wave. Low energy wave is characterized by a low amplitude. High energy wave is characterized by a high amplitude.
Therefore, the correct option is D.
1) the weight of an object at Earth's surface is given by
, where m is the mass of the object and
is the gravitational acceleration at Earth's surface. The book in this problem has a mass of m=2.2 kg, therefore its weight is
2) On Mars, the value of the gravitational acceleration is different:
. The formula to calculate the weight of the object on Mars is still the same, but we have to use this value of g instead of the one on Earth:
3) The weight of the textbook on Venus is F=19.6 N. We already know its mass (m=2.2 kg), therefore by re-arranging the usual equation F=mg, we can find the value of the gravitational acceleration g on Venus:
4) The mass of the pair of running shoes is m=0.5 kg. Their weight is F=11.55 N, therefore we can find the value of the gravitational acceleration g on Jupiter by re-arranging the usual equation F=mg:
5) The weight of the pair of shoes of m=0.5 kg on Pluto is F=0.3 N. As in the previous step, we can calculate the strength of the gravity g on Pluto as
<span>6) On Earth, the gravity acceleration is </span>
<span>. The mass of the pair of shoes is m=0.5 kg, therefore their weight on Earth is
</span>
<span>
</span>
That certain change from that ecosystem will require 50 years or longer because big ecosystems need a long time to restablize the living ecosystem.
Answer:
Skeletal system, muscular system
Explanation:
Skeletal system:
bones
Muscular system:
muscles
Together, they work together and create the musculoskeletal system.