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3 years ago

How much heat is required to heat 2 kg of water from 25°C to 40°C?

Physics

1 answer:

Dominik [7]3 years ago

5 0

Answer:

126000 J

Explanation:

Applying,

Q = cm(t₂-t₁).................. Equation 1

Where Q = Amount of heat, c = specifc heat capacity of water, m = mass of water, t₁ = Initial temperature, t₂ = Final temperature.

From the question,

Given: m = 2 kg, t₁ = 25°C, t₂ = 40°C

Constant: c = 4200 J/kg.°C

Substitute these value into equation 1

Q = 2×4200(40-25)

Q = 2×4200×15

Q = 126000 J

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The magnitude of the force associated with the gravitational field is constant and has a value FF . A particle is launched from

uysha [10]

Answer:

The kinetic energy of the particle will be 12U₀

Explanation:

Given that,

A particle is launched from point B with an initial velocity and reaches point A having gained U₀ joules of kinetic energy.

Constant force = 12F

According to question,

The kinetic energy is

$U_{0}=Fx$ ....(I)

Constant force = 12F

A resistive force field is now set up ,

Resistive force is given by,

$F_{r}=12F$

When the particle moves from point B to point A then,

We need to calculate the kinetic energy

Using formula for kinetic energy

$U=F_{r}x$

Put the value of $F_{r}$

$U=12Fx$

Now, from equation (I)

$U=12U_{0}$

Hence, The kinetic energy of the particle will be 12U₀.

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3 years ago

Driving along in your car, you take your foot off the gas, and your speedometer shows a reduction in speed. Describe an inertial

denis-greek [22]

Answer:

v ’= v + v₀

a system can be another vehicle moving in the opposite direction.

Explanation:

In an inertial reference frame the speed of the vehicle is given by the Galileo transformational

v ’= v - v₀

where v 'is the speed with respect to the mobile system, which moves with constant speed, v is the speed with respect to the fixed system and vo is the speed of the mobile system.

The vehicle's speedometer measures the harvest of a fixed system on earth, in this system v decreases, for a system where v 'increases it has to be a system in which the mobile system moves in the negative direction of the x axis, whereby the transformation ratio is

v ’= v + v₀

Such a system can be another vehicle moving in the opposite direction.

3 0

3 years ago

What is a tsunami? How is it formed?

IrinaK [193]

A tsunami is a series of waves generated in an ocean or other body of water by a disturbance such as an earthquake, landslide, volcanic eruption, or meteorite impact. ... Undersea earthquakes, which typically occur at boundaries between Earth's tectonic plates, cause the water above to be moved up or down

4 0

3 years ago

Read 2 more answers

Calculate curls of the following vector functions (a) AG) 4x3 - 2x2-yy + xz2 2

aleksandr82 [10.1K]

Answer:

The curl is $0 \hat x -z^2 \hat y -4xy \hat z$

Explanation:

Given the vector function

$\vec A (\vec r) =4x^3 \hat{x}-2x^2y \hat y+xz^2 \hat z$

We can calculate the curl using the definition

$\nabla \times \vec A (\vec r ) = \left|\begin{array}{ccc}\hat x&\hat y&\hat z\\\partial/\partial x&\partial/\partial y&\partial/\partial z\\A_x&X_y&A_z\end{array}\right|$

Thus for the exercise we will have

$\nabla \times \vec A (\vec r ) = \left|\begin{array}{ccc}\hat x&\hat y&\hat z\\\partial/\partial x&\partial/\partial y&\partial/\partial z\\4x^3&-2x^2y&xz^2\end{array}\right|$

So we will get

$\nabla \times \vec A (\vec r )= \left( \cfrac{\partial}{\partial y}(xz^2)-\cfrac{\partial}{\partial z}(-2x^2y)\right) \hat x - \left(\cfrac{\partial}{\partial x}(xz^2)-\cfrac{\partial}{\partial z}(4x^3) \right) \hat y + \left(\cfrac{\partial}{\partial x}(-2x^2y)-\cfrac{\partial}{\partial y}(4x^3) \right) \hat z$

Working with the partial derivatives we get the curl

$\nabla \times \vec A (\vec r )=0 \hat x -z^2 \hat y -4xy \hat z$

6 0

3 years ago

What is the intensity of a sound with a measured intensity level of 84 db? (i0 = 10-12 w/m2)?

Ivahew [28]

The unit measurement for sound can be expressed in terms of intensity and in decibels. The intensity of sound is the measure of its power over unit area. The common unit of measurement is in decibels. This is commonly used in measuring the extent of noise. The conversion from intensity to the decibel unit is through logarithmic function. The formula is:

dB = 10 log(I/I0), where I0 is 10^-12 Watts per square meter

Substituting the values to the equation,

84 = 10log(I/10^-12)
I = 0.0002512 W/m2

In scientific notation the intensity is 2.512 x 10^-4 W/m^2.

7 0

3 years ago