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
Answer:
(a). Index of refraction are
= 1.344 &
= 1.406
(b). The velocity of red light in the glass
2.23 ×
The velocity of violet light in the glass
2.13 ×
Explanation:
We know that
Law of reflection is

Here
= angle of incidence
= angle of refraction
(a). For red light
1 ×
=
× 
= 1.344
For violet light
1 ×
=
× 
= 1.406
(b). Index of refraction is given by

= 1.344


2.23 ×
This is the velocity of red light in the glass.
The velocity of violet light in the glass is given by

2.13 ×
This is the velocity of violet light in the glass.
Before giving you the answer straight away, I’d like to make sure you understand each option.
FIRST OPTION
“He developed the three laws of motion."
This option is not only the incorrect answer, but it is an incorrect statement. Galileo did not develop the three laws of motion. Isaac Newton was the one to compiled the three laws of motion.
SECOND OPTION
“He was the first to systematically study force and motion."
This option is a statement is true, and it could also be the correct answer. Galileo Galilei used experiments to search for the cause of motion.
THIRD OPTION
“He was the first to discover gravity."
This option is not only the incorrect answer, but it is an incorrect statement. Galileo was not the person to discover gravity. Sir Isaac Newton was the first to discover gravity.
FINAL OPTION
“He improved on Newton's laws."
This option is not only the incorrect answer, but it is an incorrect statement. Galilei did not improve Sir Isaac Newton’s laws.
Now that we’ve gone through each of the options individually, we can go ahead and determine the correct answer to the question, which is...
B ) He was the first to systematically study force and motion.
- Marlon Nunez
Its because the molecules in the solid structures are very close to each other and rigidly packed, thus due to this quantum structure they have pretty awesome speed of sound in them