Answer:
C ) 1.53
Explanation:
The critical angle of a material is given by the formula

where
c is the critical angle
n is the refractive index
This formula is valid if the second medium is air (which is the case of the problem).
In this problem, we know the critical angle:

Therefore we can rearrange the equation to find the refractive index:

vector A has magnitude 12 m and direction +y
so we can say

vector B has magnitude 33 m and direction - x

Now the resultant of vector A and B is given as

now for direction of the two vectors resultant will be given as


so it is inclined at 160 degree counterclockwise from + x axis
magnitude of A and B will be


so magnitude will be 35.11 m
Answer:
a) t = 0.74s
b) D = 4.76m
c) Vf = 5.35m/s
Explanation:
The ball starts rolling when Vf = ωf*R.
We know that:
Vf = Vo - a*t
ωf = ωo + α*t
With a sum of forces on the ball:




With a sum of torque on the ball:



Replacing both accelerations:


t=0.74s
The distance will be:


Final velocity:

Vf=5.35m/s
We use the formula V=IR where I is current, v is voltage, and R is resistance. This is V=(3)(10) which is 30 Volts, answer choice (c)