Answer:
A) - 1.8 m/s
Explanation:
As we know that whole system is initially at rest and there is no external force on this system
So total momentum of the system must be conserved
so we will have

now plug in all data into above equation



so correct answer is
A) - 1.8 m/s
It's important to know that diffraction gratings can be identified by the number of lines they have per centimeter. Often, more lines per centimeter is more useful because the images separation is greater when this happens. That is, the distance between lines increases.
<h2>Therefore, the answer is 2.</h2>
Answer:
C) China, or "Our largest trade deficit is with China"
Explanation:
China is currently our largest goods trading partner. 85% of goods are imported from China to America. The most prominent goods among the finished products exported from China were consumer electronics, data processing technologies, clothing, other textiles, optical gear, and medical equipment.
Answer:
The sound intensity of train is 1000 times greater than that of the library.
Explanation:
We have expression for sound intensity level,

A train whistle has a sound intensity level of 70 dB
We have

A library has a sound intensity level of about 40 dB
We also have

Dividing both equations

The sound intensity of train is 1000 times greater than that of the library.