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3 years ago

How much water

Physics

1 answer:

nevsk [136]3 years ago

6 0

Answer:

The mass is $m = 3.75 \ kg$

Explanation:

From the question we are told that

The initial temperature is $T_1 = 15^oC$

The final temperature is $T_2 = 100 ^o C \ (boiling point )$

Generally the maximum heat produced by 1 Liter of natural gas is $9000 \ cal$

So the amount of heat produced by 100 L is

$E = 9000 * 100$

=> $E = 9000 00 \ cal$

Generally given that the efficiency is $\eta = 0.35$

Then actual heat received by the water is

$H = 0.35 * E$

=> $H = 0.35 * 9000 00$

=> $H = 315000 \ cal$

Converting to kcal

=> $H = 315000 \ cal = \frac{315000}{1000} = 315 \ kcal$

Generally the specific heat of water is

$c_w = 1 kcal/ kg \cdot ^oC$

Generally the heat received by the water is mathematically represented as

$H = m * c_w * (T_2 - T_1)$

=> $315 = m * 1 * ( 100 - 15 )$

=> $m = 3.75 \ kg$

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Amanda [17]

Answer:

When a particle or a system of particles move in a system where no external force acts, then the total linear momentum of the particle system remains constant.

Explanation:

Given data:

Total mass of the skateboarder, $m_{1} = 70 \ kg$

Mass of the friend, $m_{2} = 50 \ kg$

Initial velocity of the skateboarder, $u_{1} = 3 \ m/s$

Initial velocity of the the friend, $u_{2} = 0$

Let the new velocity of the skateboarder when his friend jumps be $v$ .

From the conservation law of linear momentum,

$m_{1}u_{1} + m_{2}u_{2} = (m_{1} + m_{2})v$

$70 \times 3 + 50 \times 0 = (70 + 50)v$

$\Rightarrow \ v &= 1.75 \ m/s.$

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4 years ago

A spring that has a force constant of 1050 N/m is mounted vertically on the ground. A block of mass 1.95 kg is dropped from rest

aleksandrvk [35]

Answer:

25.2 cm

Explanation:

K = 1050 N/m

m = 1.95 kg

h = 1.75 m

By the conservation of energy, the potential energy of the block is converted into the potential energy stored in the spring

m g h = 1/2 x k x y^2

Where, y be the distance by which the spring is compressed.

1.95 x 9.8 x 1.75 = 1/2 x 1050 x y^2

33.44 = 525 x y^2

y = 0.252 m

y = 25.2 cm

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3 years ago

How long will it take by 50W heater to melt 100g of ice at 0degreeC? Specific heat capacity of water = 4.2J/ (g0C), latent heat

vaieri [72.5K]

Answer:

420 s

Explanation:

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3 years ago

A newly discovered planet has the same mass as the Earth, but a person standing on the surface of the planet experiences a force

Dafna11 [192]

This question deals with the acceleration due to gravity on the surface of the planet. The value of the acceleration due to gravity on the surface of two planets, that is Earth and on the surface of another planet are compared to find out the relation between the radii of both planets, provided their masses are the same.

The correct option for the radius of the new planet is "Option 3: Square Root of 3 R"

The value of the acceleration due to gravity on the surface of a planet is given by the following formula:

$g = \frac{GM}{R^2}$ ----------- eqn(1)

where,

g = acceleration due to gravity on Earth

G = Universal Gravitational Constant

M = mass of the Earth

R = Radius of the Earth

Now, the same formula for the acceleration due to gravity on the surface of the other planet can be written as follows:

$g' = \frac{GM'}{R'}\\\\$ ------------- eqn(2)

where,

g' = acceleration due to gravity on the new planet

G = Universal Gravitational Constant

M' = mass of the new planet

R' = Radius of the new planet

According to the given condition, the new planet has the same mass as the Earth's mass but the acceleration due to gravity on the surface of the new planet is one-third of the acceleration due to gravity on the surface of Earth.

$M'=M\\\\g'=\frac{1}{3}g$

using eqn (1) and eqn (2):

$\frac{GM}{R'^2}=\frac{1}{3}\frac{GM}{R^2}\\\\R'^2=3R^2\\\\R' = \sqrt{3}R$

Hence, the radius of the new planet is found to be equal to the square root of 3 times the radius of the Earth (Square Root of 3 R).

Learn more about acceleration due to gravity on the surface of a planet here:

brainly.com/question/15575318?referrer=searchResults

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3 years ago

The beautiful Multnomah Falls in Oregon are approximately 206m high. If the Columbia river is flowing horizontally at 2.90m/s ju

zhenek [66]

Answer:

The overall velocity of the water when it hits the bottom is:

$v_f=63.61\ \frac{m}{s}$

Explanation:

Use the law of conservation of energy.

Call it instant [1] to the moment when the water is just before reaching the falls.

At this moment its height h is 206 meters and its velocity horizontally $v_i$ is $v_i = 2.90$ m/s.

At the instant [1] the water has gravitational power energy $E_g$

$E_g = mgh$

The water also has kinetic energy Ek.

$E_k = 0.5mv_i ^ 2$

Then the Total E1 energy is:

$E_1 = mgh + 0.5mv_i ^ 2$

In the instant [2] the water is within an instant of touching the ground. At this point it only has kinetic energy, since the height h = 0. However at time [2] the water has maximum final velocity $v_f$

So:

$E_2 = 0.5mv_f ^ 2$

As the energy is conserved then $E_1 = E_2$

$mgh + 0.5mv_i ^ 2 = 0.5mv_f ^ 2$

Now we solve for $v_f$ .

$gh + 0.5v_i ^ 2 = 0.5v_f ^ 2\\\\9.8(206) + 0.5(2.90) ^ 2 = 0.5v_f 2\\\\v_f^2 = \frac{9.8(206) + 0.5(2.90) ^ 2}{0.5}\\\\v_f = \sqrt{\frac{9.8(206) + 0.5(2.90) ^ 2}{0.5}}\\\\v_f=63.61\ \frac{m}{s}$

7 0

3 years ago