An object is spun around in circular motion such that its frequency is 500 Hz. a. What is the period of its rotation?
b.
HowW much time will be required to complete 7 rotations?

Explanation:

Given parameters:

Frequency  = 500Hz

Unknown:

a. Period of rotation

b. Time required to complete 7 rotation

Solution:

The period of rotation is the time taken to complete a turn.

      P =

P is the period

t is the time

n is the number of turns

  Period is the inverse of frequency;

        P =   = 0.002s

b.

Time required to complete 7 rotation;

            P  =  

           t  = P x n

t is the time

P is the period

n is the number of rotations

          t  = 0.002 x 7  = 0.014s

speed of light in vacuum is 300,000 km/s

speed of light in other mediums is given by the expression v = c/n, where c is the speed of light in vacuum and n is the refractive index of medium.

for the first medium v = 200,000 km/s

  so, refractive index of medium = 300000/200000 = 1.5

    1.5 refractive index is usually for glass. so first medium is glass.

for the second medium v = 250,00 km/s

so, refractive index of medium = 300000/250000 = 1.2

    1.2 refractive index is usually for water. so second medium is water.

for the third medium v = 0 km/s

so, refractive index of medium = 300000/0 = ∞

    ∞ refractive index is usually for opaque mediums. so third medium is opaque medium.

find the surface area of the sphere to the nearest square unit. use a calculator.

a. 254 in.2

b. 64 in.2

c. 127 in.2

d. 1,018 in.2