I think it’s C sorry if it’s wrong :(
We know that arc length (x(t)) is given with the following formula:

Where r is the radius of the barrel. We must keep in mind that as barrel rolls its radius decreases because less and less tape is left on it.
If we say that the thickness of the tape is D then with every full circle our radius shrinks by d. We can write this down mathematically:

When we plug this back into the first equation we get:

We must solve this quadratic equation.
The final solution is:

It is rather complicated solution. If we asume that the tape has no thickness we get simply:
Answer:
Density is the mass to volume ratio of an object.
> It tells you how compact the mass is.
> Density = mass/volume
The density of water is 1 g/ml or 1 kg/L or 1000 kg/m3
• If an object has a density less than that of water, it
will float.
• If an object has a density more than that of water, it
will sink
Explanation:
hope this helps some
Answer:
Explanation:
velocity of light in a medium of refractive index V = V₀ / μ
V₀ is velocity of light in air and μ is refractive index of light.
time to travel in tube with air = length of tube / velocity of light
8.72 ns = L / V₀ L is length of tube .
time to travel in tube with jelly = length of tube / velocity of light
8.72+ 1.82 = L / V L is length of tube .
10.54 ns = L / V
dividing the equations
10.54 / 8.72 = V₀ / V
10.54 / 8.72 = μ
1.21 = μ
refractive index of jelly = 1.21 .