Answer:
The combined velocity is 8.61 m/s.
Explanation:
Given that,
The mass of a truck, m = 2800 kg
Initial speed of truck, u = 12 m/s
The mass of a car, m' = 1100 kg
Initial speed of the car, u' = 0
We need to find the combined velocity the moment they stick together. Let it is V. Using the conservation of momentum.

So, the combined velocity is 8.61 m/s.
Answer:
Maximum Radius = 2.89m
Explanation:
The maximum radius will be determined by the angle of incidence which is equal to the critical angle. Now, any angle larger than that will make the light to be totally internally reflected. Hence, we can figure out that angle from Snell’s law where the refracted angle is 90°, and then use the tangent function.
From Snell's law;
n_air*sin90° = n_water*sin(θ _c)
Where;
θ_c is the critical angle
Refractive index of water; n_water = 1.333
Refractive index of air;n_air = 1
Thus;
1*1 = 1.33sinθ_c
sinθ_c = 1/1.33
θ_c = sin^(-1)0.7519
θ_c = 48.76°
Like I said earlier, we'll use tangent to find the radius.
Thus;
tanθ_c = d/R
From the question, d = 3.3m
Thus;
3.3/tan48.76 = R
So, R = 2.89m
The answer is C. how much space in three dimensions the object occupies