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3 years ago

A water heater warms 35 l of water from a temperature of 22.7 c to a temperature of 83.7

1 answer:

8 0

The amount of energy needed to increase the temperature of a substance by $\Delta T$ is given by
$Q=m C_s \Delta T$
where
m is the mass of the substance
$C_s$ is its specific heat capacity
$\Delta T$ is the increase in temperature

The water volume is $V=35 L= 35 dm^3 = 0.035 m^3$ , since its density is $d=1000 kg/m^3$ , the mass of this sample of water is
$m=dV=(1000 kg/m^3)(0.035 m^3)=35 kg$

The water specific heat capacity is $C_s = 4.18 kJ/kg ^{\circ}C$

and the increase in temperature is $\Delta T=83.7 ^{\circ}C-22.7 ^{\circ}C=61^{\circ}C$

Therefore, the amount of energy needed is
$Q=mC_s \Delta T=(35 kg)(4.18 kJ/kg ^{\circ}C)(61^{\circ}C)=8924 kJ = 8.92 \cdot 10^6 J$

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Describe the advantages and disadvantages of keeping the road clear of ice

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A advantage is less car accidents and a disadvantage is, in order to keep the roads clear of ice is a chemical. Like salt. Which is bad for the animals.

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3 years ago

When the frequency of an ac circuit is decreased, the current in the circuit increases. which combination of elements is most li

zaharov [31]

Answer:

The combination of elements most likely to comprise the circuit are resistor, inductor and capacitor

Explanation:

The impedance of an LCR circuit shown as

Z = √R² + (X↓l - X↓c)²

Z = √R² + (2π∨L - 1/2π∨c)²

Variation of Z with respect to υ is shown in the figure.

As υ increases, Z decreases and so the current increases.

At υ = υ↓r

Z is minimum, current is maximum. Beyond

υ = υ↓r

Z increases and so current decreases.

so the combination of circuit elements that is most suitable to comprise

the circuit is R, L and C.

To learn more about these circuits

brainly.com/question/13140756

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1 year ago

A ball is held at rest at the top of a hill. The ball is then released and starts rolling down the hill. At the bottom it reache

Alex17521 [72]

Answer:

Gravitational Potential Energy

Explanation:

a ball is held rest at the top of hill

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it. and body will start move downward and its potential energy will convert into kinetic energy due to motion of body

at the ground level it will stop and potential energy will became zero and kinetic energy get convert into internal energy due to collisions

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2 years ago

A swing has a period of 10 seconds. What is its frequency ?

kow [346]

Frequency = 1 / (period)

Frequency = 1 / (10 seconds) = (1/10) ( / second) = 0.1 per second = <em>0.1 Hz</em>.

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2 years ago

Henrietta is going off to her physics class, jogging down the sidewalk at a speed of 2.70 m/s. Her husband Bruce suddenly realiz

Katen [24]

Answer:

The velocity is $v = 6.66 \ m/s$

Henrietta is at distance $s= 18.17 \ m$ from the under the window

Explanation:

From the question we are told that

The speed of Henrietta is $v= 2.70 \ m/s$

The height of the window from the ground is $h = 36.5 \ m$

Generally the time taken for the lunch to reach the ground assuming it fell directly under the window is

$t = \sqrt{\frac{2 * h }{g} }$

=> $t = \sqrt{\frac{2 * 36.5 }{9,8} }$

=> $t = 2.73 \ s$

Generally the time taken for the lunch to reach Henrietta is mathematically represented as

$T = t + t_1$

Here $t_1$ is the time duration that elapsed after Henrietta has passed below the window the value is given as 4 s

Now

$T = 2.73 + 4$

=> $T = 6.73 \ s$

Generally the distance covered by Henrietta before catching her lunch is

$s= v * T$

=> $s= 2.70 * 6.73$

=> $s= 18.17 \ m$

Generally the speed with which Bruce threw her lunch is mathematically represented as

$v = \frac{18.17}{2.73}$

$v = 6.66 \ m/s$

4 0

3 years ago