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3 years ago

Undersoil electrical heating systems are used in greenhouses. This system could also be

Physics

1 answer:

Nata [24]3 years ago

4 0

Answer:t

Explanation:

Given that,

Power output is

P = 0.50kW = 0.5 × 1000 = 500W.

We want to find energy transfer in

t = 2minutes = 2 × 60 = 120 seconds

Also, time to hour

t = 2/60 = 1/30 hour

Power is the rate of energy.

Therefore,

Power = energy / time taken

Energy = power × time taken

Energy = 0.5kW × 1/30 hr

Energy = 0.01667 kWh

Also, energy in Joule

Energy = power × time

Energy = 500W × 120s

Energy = 60,000J

Energy = 60kJ.

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A certain resistor dissipates 0.5 W when connected to a 3 V potential difference. When connected to a 1 V potential difference,

Stels [109]

Answer:

Explanation:

$Power = IV$

From ohms law we know that

$V= IR\\\\I= \frac{V}{R} \\\\Power= \frac{V}{R}*V\\\\Power= \frac{V^2}{R}$

Given data

P1 = 0.5 Watt

P2 = ?

V1= 3 Volts

V2= 1 Volt

Thus we can solve for the power dissipated as follows

$P1= \frac{V1^2}{R1}\\\\P2= \frac{V2^2}{R2}$

$\frac{P1}{P2} = \frac{V1^2}{V2^2}\\\\ P2=\frac{ V2^2}{ V1^2} *P1\\\\ P2=\frac{ 1^2}{ 3^2} *0.5= 0.055= 0.056 W$

<em>The resistor will dissipate 0.056 Watt</em>

7 0

3 years ago

In the mobile m1=0.42 kg and m2=0.47 kg. What must the unknown distance to the nearest tenth of a cm be if the masses are to be

LuckyWell [14K]

Complete Question

The complete question is shown on the first uploaded image

Answer:

Explanation:

From he question we are told that

The first mass is $m_1 = 0.42kg$

The second mass is $m_2 = 0.47kg$

From the question we can see that at equilibrium the moment about the point where the string holding the bar (where $m_1 \ and \ m_2$ are hanged ) is attached is zero

Therefore we can say that

$m_1 * 15cm = m_2 * xcm$

Making x the subject of the formula

$x = \frac{m_1 * 15}{m_2}$

$= \frac{0.42 * 15}{0.47}$

$x = 13.4 cm$

Looking at the diagram we can see that the tension T on the string holding the bar where $m_1 \ and \ m_2$ are hanged is as a result of the masses ( $m_1 + m_2$ )

Also at equilibrium the moment about the point where the string holding the bar (where ( $m_1 +m_2$ ) and $m_3$ are hanged ) is attached is zero

So basically

$(m_1 + m_2 ) * 20 = m_3 * 30$

$(0.42 + 0.47) * 20 = 30 * m_3$

Making $m_3$ subject

$m_3 = \frac{(0.42 + 0.47) * 20 }{30 }$

$m_3 = 0.59 kg$

3 0

3 years ago

Which object will be considered to be in free fall

Pani-rosa [81]

It depends on what they are

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3 years ago

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Which descriptions best fit the labels? X: kinetic energy Y: potential energy X: potential energy Y: kinetic energy X: mechanica

Pani-rosa [81]

W-APE. For example, work W done to accelerate a positive charge from rest is positive and results from a loss in PE, or a negative APE. There must be a minus sign in front of APE to make W positive. PE can be found at any point by taking one point as a reference and calculating the work needed to move a charge to the other point.

( The capital A’s in the words are supposed to be triangles ! I also hoped this helped ! Please mark me as brainliest !! )

3 0

3 years ago

Which of the following is an example of homeostasis?

Bogdan [553]

The answer is : D

Reasoning:
Homeostasis is the body’s balance

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3 years ago

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