B- lack of control.
the scientists did not have a proper control group.
Answer:

Explanation:
The refractive index of a medium is a measure to know how much the speed of light within the medium is reduced. It can be calculated with the next equation:
(1)
Where:


The speed of light in the vacuum is approximately 300,000 km/s. In order to work with the same units let's do the proper conversion with the velocity of the medium:

Finally, replacing the data in (1):

Answer:
50kg.m/s
Explanation:
In order to find momentum you must use the formula P=mv
p= momentum
m=mass
v= velocity
so in other words, momentum= mass times velocity
or in this case, momentum= 10 times 5 :)
We're u can never put it back together
Answer:
Explanation:
Given a particle of mass
M = 1.7 × 10^-3 kg
Given a potential as a function of x
U(x) = -17 J Cos[x/0.35 m]
U(x) = -17 Cos(x/0.35)
Angular frequency at x = 0
Let find the force at x = 0
F = dU/dx
F = -17 × -Sin(x/0.35) / 0.35
F = 48.57 Sin(x/0.35)
At x = 0
Sin(0) =0
Then,
F = 0 N
So, from hooke's law
F = -kx
Then,
0 = -kx
This shows that k = 0
Then, angular frequency can be calculated using
ω = √(k/m)
So, since k = 0 at x = 0
Then,
ω = √0/m
ω = √0
ω = 0 rad/s
So, the angular frequency is 0 rad/s