Answer: The velocity of the first ball is 0.875 m/s if the second ball travels at 1.5 m/s after collision.
Explanation:
Given:
= 0.2 kg,
= 0.15 kg
= 2 m/s,
= 0 m/s,
= ?,
= 1.5 m/s
Formula used is as follows.

where,
v = velocity before collision
v' = velocity after collision
Substitute the values into above formula as follows.

Thus, we can conclude that the velocity of the first ball is 0.875 m/s if the second ball travels at 1.5 m/s after collision.
Answer:
3
Explanation:
Subscript basically tells you the number of element or ions present in a compound. In this case the subscript of carbon which is 3 denotes that only three carbon atoms is present in the compound.
This problem is providing the ratio of nitrogen to oxygen by mass in nitrogen monoxide, NO, as 7.0:8.0 and asks for the same ratio but in NO₂ and N₂O₇. After doing the calculations, the results are 7.0:16.0 and 1.0:4.0 respectively.
<h3>Mass ratios:</h3>
In chemistry, one can calculate the mass ratios in chemical formulas according to the atomic mass of each atom. In such a way, one knows the mass ratio of nitrogen to oxygen in NO is 7.0:8.0 because we divide the atomic mass of nitrogen by oxygens:

Now, for chemical formulas with subscripts, one must multiply the atomic mass of the element by the subscript in the formula, which is the case of NO₂ and N₂O₇ as shown below:

Therefore, the results for NO₂ and N₂O₇ are 7.0:16.0 and 1.0:4.0 respectively
Learn more about atomic masses: brainly.com/question/5566317
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