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What is the angular speed of (a) the second hand, (b) the minute hand, and (c) the hour hand of a smoothly running analog watch?

Agata [3.3K]

A)We know the formula of the angular speed is ω = 2π / TWhere T is the time period.When second hand completes one revolution then the time taken is 60s.So T = 60sThen the angular speed of the second hand is ω= 2π / (60s) = 0.1047 rad/sb)When the minute hand completes one revolution the time taken is T = 1 hr = 3600sThen the angular speed of the minute hand is ω =(2π) / (3600s) = 0.001745 rad/sc)When the hour hand completes one revolution then the timeperiod is T = 12hrs = (12)(3600)sThen the angular speed of the hour hand is ω =(2π) / [(12)(3600)s] = 1.45444 x 10^-4 rad/s

8 0

3 years ago

How light is channelled down an optical fibre

coldgirl [10]

Explanation:

Suppose you want to shine a flashlight beam down a long, straight hallway. Just point the beam straight down the hallway -- light travels in straight lines, so it is no problem. What if the hallway has a bend in it? You could place a mirror at the bend to reflect the light beam around the corner. What if the hallway is very winding with multiple bends? You might line the walls with mirrors and angle the beam so that it bounces from side-to-side all along the hallway. This is exactly what happens in an optical fiber.

The light in a fiber-optic cable travels through the core (hallway) by constantly bouncing from the cladding (mirror-lined walls), a principle called total internal reflection. Because the cladding does not absorb any light from the core, the light wave can travel great distances.

However, some of the light signal degrades within the fiber, mostly due to impurities in the glass. The extent that the signal degrades depends on the purity of the glass and the wavelength of the transmitted light (for example, 850 nm = 60 to 75 percent/km; 1,300 nm = 50 to 60 percent/km; 1,550 nm is greater than 50 percent/km). Some premium optical fibers show much less signal degradation -- less than 10 percent/km at 1,550 nm.

1

3 0

3 years ago

Consider and mass of a material

Leni [432]

Answer:Density is the mass of an object divided by its volume. Density often has units of grams per cubic centimeter (g/cm3). ... You probably have an intuitive feeling for density in the materials you use often. For example, sponges are low in density; they have a low mass per unit volume.

Explanation:

3 0

2 years ago

I neeed help im so comfused Points Possible: 1, Points Correct: 0 Which group of numbers is listed from greatest to least? -3, -

Alona [7]

The groups aren't well formatted ;

The groups are ;

(-3, -1, 0, 2, 7) ; (9, 7, 6, -5, -4) ; (8, -6, 5, -4, 1) ; (-3, -4, -7, -8, -9)

Answer:

(-3, -4, -7, -8, -9)

Explanation:

Given the following group of numbers :

Evaluating each group of values for which is correctly arranged from greatest to least.

(-3, -1, 0, 2, 7) : - 1 is greater than - 3 (the group isn't arranged from greatest to least)

(9, 7, 6, -5, -4) : - 4 is greater than - 5 ; hence, the group isn't arranged from greatest to least

(8, -6, 5, -4, 1) : 5 is greater than - 6 ; hence, the group isn't arranged from greatest to least

(-3, -4, -7, -8, -9) ; the group of numbers here is arranged from greatest to least ;

(-3 > -4 > -7 > -8 > -9) ; hence, the correct group

5 0

2 years ago

If a box has a length of 10.0 cm, a width of 20.0 cm, and a height of 5.00 cm, then what is its volume in m^3?

lesya692 [45]

Explanation:

Solution,

Given:-

Length=10 cm
Width= 20 cm
Height= 5 cm
Volume =?

Now,

By using the formula of volume of a cuboid, we have

volume=length×width×height
volume=10 cm×20 cm×5 cm
volume=1000 cm³
volume= 1×10×10×10×10 cm³
volume=(1×10⁴) cm³

Hence, last option is the correct answer.

6 0

3 years ago