3 years ago

URGENT HELP PLEASE WILL AWARD BRAINLIEST!!!!!

Physics

1 answer:

dexar [7]3 years ago

6 0

Answer:

2.B 4.C 5.also C 7.A 10.D

Explanation:

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A power plant produces 1000 MW to supply a city 40 km away. Current flows from the power plant on a single wire of resistance 0.

nikitadnepr [17]

Answer:

Current = 8696 A

Fraction of power lost = $\dfrac{80}{529}$ = 0.151

Explanation:

Electric power is given by

$P=IV$

where I is the current and V is the voltage.

$I=\dfrac{P}{V}$

Using values from the question,

$I=\dfrac{1000\times10^6 \text{ W}}{115\times10^3\text{ V}} = 8696 \text{ A}$

The power loss is given by

$P_\text{loss} = I^2R$

where R is the resistance of the wire. From the question, the wire has a resistance of $0.050\Omega$ per km. Since resistance is proportional to length, the resistance of the wire is

$R = 0.050\times40 = 2\Omega$

Hence,

$P_\text{loss} = \left(\dfrac{200000}{23}\right)^2\times2$

The fraction lost = $\dfrac{P_\text{loss}}{P}=\left(\dfrac{200000}{23}\right)^2\times2\div (1000\times10^6)=\dfrac{80}{529}=0.151$

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3 years ago

A convex mirror has a focal length of -12 cm. A lightbulb with

horrorfan [7]

Answer:

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Explanation:

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2. How long must a 400 W electrical engine work in order to produce 300 kJ of work?

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Answer:

Explanation:

400 W = 400 J/s

300000 J / 400 J/s = 750 s or 12.5 minutes

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The rate at which the earth's surface loses heat and keeps earth temperature at which living things can survive

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What type of force is needed for motion to occur?

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Answer:

Forces include gravity, friction, and applied force. Force causes changes in the speed or direction of motion. These changes are called acceleration

Explanation:

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2 years ago

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