<u>Answer:</u> The ball is travelling with a speed of 5.5 m/s after hitting the <u>bottle.</u>
<u>Explanation:</u>
To calculate the speed of ball after the collision, we use the equation of law of conservation of momentum, which is given by:

where,
are the mass, initial velocity and final velocity of ball.
are the mass, initial velocity and final velocity of bottle.
We are given:

Putting values in above equation, we get:

Hence, the ball is travelling with a speed of 5.5 m/s after hitting the bottle.
A good hypothesis describes your ideas and how you think the experiment will conclude. Additionally, hypotheses have scientific information included.
Answer:
the car with the hay should slow to 16m/s if the bale of hay is dropped into it.
Answer: critical angle, sin^-1 (n2/n1)
Explanation: the angle of incidence at which the retracted ray makes an angle of 90° with the normal is known as the critical angle.
Snell's law defined refraction mathematically as shown below
n1 sin θi = n2 sin θr
n1 = refractive index of the first medium
n2 = refractive index of the second medium
θi = angle of incidence
θr = angle of refraction
When the refrafted ray is perpendicular to the normal, the angle of refraction (θr) is 90° hence making the angle of incidence (θi) the critical angle θc
By substituting these conditions into the Snell's law, we have that
n1 sin θc = n2 sin 90
According to trigonometry, the value of sin 90 is 1, hence we have that
n1 sin θc =n2
sin θc = n2/n1
θc = sin^-1 (n2/n1)