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3 years ago

A disk of radius 25 cm spinning at a rate of 30 rpm slows to a stop over 3 seconds. what is the angular acceleration?

Physics

1 answer:

SCORPION-xisa [38]3 years ago

5 0

Answer:

α = -π/3 rad/s²

θ = 1.5π rad ≈ 4.71 rad

θ = 0.75 rev

Explanation:

30 rev/min (2π rad/rev) / (60 s/min) = π rad/s

α = (ωf - ωi) / t = (0 - π) / 3 = -π/3 rad/s²

θ = ½αt² = ½(π/3)3² = 1.5π rad ≈ 4.71 rad

θ = 1.5π rad / 2π rad/rev = 0.75 rev

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Hydrogen is in Group 1A of the periodic table, known as the alkali metals, although it obviously isn't a metal. What is the reas

jeka57 [31]

It's highly reactive and contains only one valence electron

6 0

3 years ago

A device called an insolation meter is used to measure the intensity of sunlight. It has an area of 100 cm2 and registers 6.50 W

labwork [276]

Answer:

Explanation:

Intensity of the sunlight is expressed as I = Power/cross sectional area. It is measured in W/m²

Given parameters

Power rating = 6.50Watts

Cross sectional area = 100cm²

Before we calculate the intensity, we need to convert the area to m² first.

100cm² = 10cm * 10cm

SInce 100cm = 1m

10cm = (10/100)m

10cm = 0.1m

100cm² = 0.1m * 0.1m = 0.01m²

Area (in m²) = 0.01m²

Required

Intensity of the sunlight I

I = P/A

I = 6.5/0.01

I = 650W/m²

Hence, the intensity of the sunlight in W/m² is 650W/m²

4 0

3 years ago

Forms when heat, pressure, or fluids act on igneous, sedimentary, or other metamorphic rock to change its form or composition, o

BARSIC [14]

I think its a metamorphic rock because i know 100% that a metamophic rocks are created by heat and pressure

4 0

3 years ago

Red light of wavelength 633 nm from a helium-neon laser passes through a slit 0.400mm wide. The diffraction pattern is observed

kogti [31]

Answer:

a) $y_{first}=5.3mm$

b) $y_{second}=10.6-5.3 =5.3 mm$

Explanation:

The width of the central bright in this diffraction pattern is given by:

$y=\frac{m\lambda D}{a}$ when m is a natural number.

here:

m is 1 (to find the central bright fringe)
D is the distance from the slit to the screen
a is the slit wide
λ is the wavelength

So we have:

$y_{first}=\frac{633*10^{9}*3.35}{0.0004}$

$y_{first}=5.3mm$

Now, if we do m=2 we can find the distance to the second minima.

$y_{2}=\frac{2*633*10^{9}*3.35}{0.0004}$

$y_{2}=10.6 mm$

Now we need to subtract these distance, to get the width of the first bright fringe :

$y_{second}=10.6-5.3 =5.3 mm$

I hope it heps you!

4 0

3 years ago

A stone that starts at rest free falls for 7.0 s. How far does the stone fall in this time?

vredina [299]

Gravitational acceleration is approx 9.8 m/s
Time is 7s

a=9.8 m/s
t=7s

a = d/t^2

therefore:

d = a * t^2

d = 9.8 * 7^2

d = 9.8 * 49

d = 480.2 [m]

7 0

3 years ago