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:
A hot air balloon taking off
Explanation:
Two hydrogen and two oxygen multiply for two
the mass number of fluorine (F) is 19
C. 19
Answer:
Yes.
Explanation:
It should be noted that the meaning of molarity is the ratio of moles of solute per liter of solution.
It should be understood that when determining or finding the molarity of an unknown compound ,the process should be performed or carried out at least 3 times. This is done to remove any form of doubt.
The first calculated value for the concentration of the compound will be regarded as rough value, while the second and the third will be regarded as the first and second values respectively.
In this case, the third value for the concentration of HCl will be calculated to for confirmation of other value, that is to be finally sure of its concentration.