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3 years ago

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The average lifespan of an incandescent lightbulb (at 60 W) is 1,200 hours. How much energy does the incandescent lightbulb use

during its lifetime? (Answer in (60W = 0.06kW)

1 answer:

grigory [225]3 years ago

3 0

Answer:

0072.00kW

Explanation:

1,200 hours multiply by 60W will give you 72000kW. Convert it to kW. That will give you 0072.00kW.

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An object in a certain direction with an acceleration in the perpendicular direction

geniusboy [140]

Answer:

An object moving in certain direction with an acceleration in the perpendicular direction. The above condition is possible . Example of such situation in life would be when stone tied to a string whirling in a circular path

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3 years ago

Nonrenewable resources are natural resources that are limited in supply and cannot be replaced as quickly as they are used up.

zysi [14]

Answer:

True

Explanation:

Nonrenewable resources ARE limited in supply. They don't get replaced at the speed they get made. For example: we pump crude oil from the ground at a rate that makes it impossible for crude oil to be replaced. Crude oil takes millions of years to produce

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3 years ago

Which of these is a mixture?

PSYCHO15rus [73]

Answer:

Air is a mixture.

Explanation:

Air is a homogeneous mixture. It is made up of gaseous substances such as nitrogen, oxygen, and smaller amounts of others.

Carbon dioxide is a pure substance, not a mixture.

Carbon is another pure substance, it cannot be separated into other substances.

Oxygen is just oxygen, it does not contain any other substance.

5 0

4 years ago

Read 2 more answers

A spherical capacitor contains a charge of 3.00 nC when connected to a potential difference of 230 V. If its plates are separate

Assoli18 [71]

Answer:

Part(a): the capacitance is 0.013 nF.

Part(b): the radius of the inner sphere is 3.1 cm.

Part(c): the electric field just outside the surface of inner sphere is $\bf{2.81 \times 10^{4}~n~C^{-1}}$ .

Explanation:

We know that if 'a' and 'b' are the inner and outer radii of the shell respectively, 'Q' is the total charge contains by the capacitor subjected to a potential difference of 'V' and ' $\epsilon_{0}$ ' be the permittivity of free space, then the capacitance (C) of the spherical shell can be written as

$C = \dfrac{4 \pi \epsilon_{0}}{(\dfrac{1}{a} - \dfrac{1}{b})}~~~~~~~~~~~~~~~~~~~~~~~~~~~(1)$

Part(a):

Given, charge contained by the capacitor Q = 3.00 nC and potential to which it is subjected to is V = 230V.

So the capacitance (C) of the shell is

$C &=& \dfrac{Q}{V} = \dfrac{3 \times 10^{-90}~C}{230~V} = 1.3 \times 10^{-11}~F = 0.013~nF$

Part(b):

Given the inner radius of the outer shell b = 4.3 cm = 0.043 m. Therefore, from equation (1), rearranging the terms,

$&& \dfrac{1}{a} = \dfrac{1}{b} + \dfrac{1}{C/4 \pi \epsilon_{0}} = \dfrac{1}{0.043} + \dfrac{1}{1.3 \times 10^{-11} \times 9 \times 10^{9}} = 31.79\\&or,& a = \dfrac{1}{31.79}~m = 0.031~m = 3.1~cm$

Part(c):

If we apply Gauss' law of electrostatics, then

$&& E~4 \pi a^{2} = \dfrac{Q}{\epsilon_{0}}\\&or,& E = \dfrac{Q}{4 \pi \epsilon_{0}a^{2}}\\&or,& E = \dfrac{3 \times 10^{-9} \times 9 \times 10^{9}}{0.031^{2}}~N~C^{-1}\\&or,& E = 2.81 \times 10^{4}~N~C^{-1}$

3 0

3 years ago

if a torque of 55.0 N/m is required and the largest force that can be exerted by you is 135 N what is th e length of the lever a

Whitepunk [10]

Answer:

$r=0.41m$

Explanation:

Torque is defined as the cross product between the position vector ( the lever arm vector connecting the origin to the point of force application) and the force vector.

$\tau=r\times F$

Due to the definition of cross product, the magnitude of the torque is given by:

$\tau=rFsin\theta$

Where $\theta$ is the angle between the force and lever arm vectors. So, the length of the lever arm (r) is minimun when $sin\theta$ is equal to one, solving for r:

$r=\frac{\tau}{F}\\r=\frac{55\frac{N}{m}}{135N}\\r=0.41m$

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3 years ago