Water is pouring into a conical tank at the rate of 8 cubic feet per minute. If the height of the tank is 10 feet and the radius of its circular opening is 4 feet, how fast is the water level rising when the water is 4 feet deep

Explanation:

We are given that

Height of tank=h=10 ft

Radius of tank, r=4 feet

We have to find the dh/dt when the water is 4 feet deep.

Volume of cone ,

Substitute the values

Volume of cone ,

Differentiate w.r.t t

Substitute the values

answer: the correct answer id option(d).

explanation:

snell's law refraction:

the angle of refraction =

the angle of incidence =

refractive index of air = = 1

refractive index of glycerol = 1.47

from the given options, the most closest answer to 63.72° is 65° of option (d).

gravity

explanation: