Answer:
Final speed of striped ball is 3 m/s in left direction .
Explanation:
Given :
Two billiard ball with the same mass moves toward the left at the same speed 3 m/s .
Let , us assume right hand side direction to be positive and left hand side direction to be negative .
Also , let speed of ball after collision is (striped ball ) u and (solid ball) v .
It is also given that the collision is elastic .
Therefore , kinetic energy is conserved .
...... ( 1 )
Also , by conserving linear momentum .
We get :
...... ( 2 )
Putting value of u from equation 2 to equation 1 .
We get :

And , u = -3 m/s .
Therefore , final speed of striped ball is 3 m/s in left direction .
Hence , this is the required solution .
Answer:
I would think the answer is color, if the wavelength is within the visible light spectrum. This could be answered in different ways but I'm pretty sure the answer you are looking for is hue/color.
The acceleration of gravity (on Earth) is 9.8 m/s² downward.
This means that every falling object gains 9.8 m/s more downward speed
every second that it falls.
In 5 seconds of falling, it gains (5 x 9.8 m/s) = 49 m/s of downward speed.
If it was already descending at 2.0 m/s at the beginning of the 5 sec,
then at the end of the 5 sec it would be descending at
(2 m/s + 49 m/s) = 51 m/s .