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3 years ago

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Trucks can be run on energy stored in a rotating flywheel, with an electric motor getting the flywheel up to its top speed of 20

0π rad/s. Suppose that one such flywheel is a solid, uniform cylinder with a mass of 500 kg and a radius of 1.0 m. (a) What is the kinetic energy of the flywheel after charging? (b) If the truck uses an average power of 8.0 kW, for how many minutes can it operate between chargings?

1 answer:

Genrish500 [490]3 years ago

3 0

Answer:

The time it can operate between chargins in minutes is

$t=102.8 minutes$

Explanation:

Given: $m=500kg$ , $r=1.0m$ , $w=200\pi rad/s$

a). The rotational kinetic energy

$K_R=\frac{1}{2}*I*w^2$

$I=\frac{1}{2}*m*r^2$

$I=\frac{1}{2}*500kg*(1.0m)^2$

$I=250 kg*m^2$

$K_R=\frac{1}{2}*250kg*m^2*(200\pi rad/s)^2$

$K_R=49.348x10^6J$

b). The power average 0.8kW un range time can be find

$P=\frac{K_R}{t'}$

Solve to t'

$t=\frac{K_R}{P}$

$t=\frac{49.348x10^6}{0.8x10^3w}=6168.5s$

$t=6168.5s\frac{1minute}{60s}=102.8 minutes$

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As you may well know, placing metal objects inside a microwave oven can generate sparks. Two of your friends are arguing over th

poizon [28]

Answer:

$4.048\times 10^{-7}\ m$

Explanation:

h = Planck's constant = $6.626\times 10^{-34}\ m^2kg/s$

c = Speed of light = $3\times 10^8\ m/s$

E = Energy = $4.91\times 10^{-19}\ J$

Wavelength ejected is given by

$\lambda=\dfrac{hc}{E}\\\Rightarrow \lambda=\dfrac{6.626\times 10^{-34}\times 3\times 10^8}{4.91\times 10^{-19}}\\\Rightarrow \lambda=4.048\times 10^{-7}\ m$

The maximum wavelength in angstroms of the radiation that will eject electrons from the metal is $4.048\times 10^{-7}\ m$

4 0

3 years ago

A main difference between asteroids and comets is that asteroids are mostly made of rock and comets are mostly made of metals ca

avanturin [10]

We can confirm that the difference between a comet and an asteroid lies in their compositions and physical characteristics <u>derived from those compositions</u>.

As stated in the question, the main difference between an asteroid and a comet is their compositions, meaning the materials from which they form.

Asteroids are rocky objects which a heavy metal composition, while comets tend to be made of dust, ice, and <em><u>some </u></em>rocky material. Some extra differences include:

Comets reflect a steady amount of light (because of their ice composition)
Asteroids will <em><u>reflect light at random intervals due to some metals that may be present on their surface</u></em>
Comets tend to have a tail made of water from the melting ice when reflecting sunlight.

Therefore, we can confirm that the main difference between asteroids and comets is their compositions, which lead to distinct physical characteristics.

To learn more visit:

brainly.com/question/1333558?referrer=searchResults

5 0

2 years ago

Three charges, q1 = +2.06 x 10-9 C, q2 = -3.27 x 10-9 C, and q3 = +1.05 x 10-9 C, are located on the x-axis at x1 = 0, x2 = 10.0

lisov135 [29]

Answer:

The resultant force on charge 3 is Fr= -2,11665 * 10^(-7)

Explanation:

Step 1: First place the three charges along a horizontal axis. The first positive charge will be at point x=0, the second negative charge at point x=10 and the third positive charge at point x=20. Everything is indicated in the attached graph.

Step 2: I must calculate the magnitude of the forces acting on the third charge.

F13: Force exerted by charge 1 on charge 3.

F23: Force exerted by charge 2 on charge 3.

K: Constant of Coulomb's law.

d13: distance from charge 1 to charge 3.

d23: distance from charge 2 to charge 3

Fr: Resulting force.

q1=+2.06 x 10-9 C

q2= -3.27 x 10-9 C

q3= +1.05 x 10-9 C

K=9-10^9 N-m^2/C^2

d13= 0,20 m

d23= 0,10 m

F13= K * (q1 * q3)/(d13)^2

F13=9,7335*10^(-8) N

F23=K * (q2 * q3)/(d23)^2

F23= -3,09 * 10^(-7)

Step 3: We calculate the resultant force on charge 3.

Fr=F13+F23= -2,11665 * 10^(-7)

3 0

3 years ago

In a house 5 bulbs of 25 watts each are used for 6 hours a day.Calculate the unit of electricity consumed in a month of 30 days.

Svetradugi [14.3K]

(5 bulbs) x (25 watt/bulb) x (6 hour/day) x (30 day/month) =

   (5 x 25 x 6 x 30) watt-hour/month =

   22,500 watt-hour/month .

The most common unit of electrical energy used for billing purposes
is the 'kilowatt-hour' = 1,000 watt-hours .

   22,500 watt-hour/month = <em>22.5 kWh/month</em>.

   (22.5 kWh/month) x (1.50 Rs/kWh) = <em>33.75 Rs / month

</em>

4 0

3 years ago

The deck of a bridge is suspended 235 feet above a river. If a pebble falls off the side of the bridge, the height, in feet, of

Aleks04 [339]

Answer:

(a) 1, average velocity = -65.6 m/s

2, average velocity = -64.8 m/s

3, average velocity = -64.16 m/s

(b) The instantaneous velocity is -96 m/s

Explanation:

(a)

Average velocity is given by;

$y(t_2,t_1) = \frac{y(t_2) - y(t_1)}{t_2-t_1}$

(1)

$y(2.1,2) = \frac{(235-16*2.1^2) - (235-16*2^2)}{2.1-2}\\\\ y(2.1,2) = -65.6 \ m/s$

(2)

$y(2.05,2) = \frac{(235-16*2.05^2) - (235-16*2^2)}{2.05-2}\\\\ y(2.05,2) = -64.8 \ m/s$

(3)

$y(2.01,2) = \frac{(235-16*2.01^2) - (235-16*2^2)}{2.01-2}\\\\ y(2.01,2) = -64.16 \ m/s$

b. y = 235 - 16t²

The instantaneous velocity is given by;

v = dy /dt

dy / dt = -32t

when t = 3 s

v = -32(3)

v = -96 m/s

5 0

3 years ago