The heat of fusion of copper is 205000 J/kg. What is the mass of a copper rod that takes 4950000000 J of energy to melt the rod. Be sure to put the correct unit at the end of your answer and also for your final answer, place your final numbers two places after the decimal and round.​

Answer:

The formula is dimensionally correct.

Explanation:

Given

[tex]s = ut + \frac{1}{2}at^2[/tex]

Required

Prove its correctness

Write out the dimension of each:

[tex]s = M^0LT^0[/tex] --- displacement

[tex]ut = M^0LT^{-1} * T[/tex] --- velocity * time

[tex]\frac{1}{2}at^2 = M^0LT^{-2} * T^2[/tex] --- acceleration * square of time

The expression becomes:

[tex]s = ut + \frac{1}{2}at^2[/tex]

[tex]M^0LT^0 = M^0LT^{-1} * T + M^0LT^{-2} * T^2[/tex]

Apply law of indices

[tex]M^0LT^0 = M^0LT^{-1+1} + M^0LT^{-2+2}[/tex]

[tex]M^0LT^0 = M^0LT^{0} + M^0LT^{0}[/tex]

[tex]M^0LT^0 = M^0LT^{0}[/tex]

Both sides of the equation are equal

Answer:

Instantaneous velocity  [tex]= 20[/tex] meter per second

Instantaneous acceleration  [tex]= 6[/tex] meter per second square

Explanation:

Given equation of distance X = [tex]2t+3t^2[/tex]

Instantaneous velocity [tex]= \frac{dX}{dt}[/tex]  [tex]= 2 + 6 t[/tex]

Substituting the value of t = 3 seconds, we get -

[tex]\frac{dX}{dt} = 2 + 6*3 = 20[/tex] meter per second

Instantaneous acceleration  [tex]= \frac{d^2X}{dt^2}[/tex]  [tex]= 6[/tex] meter per second square

Answer:

a)    I= I₀ (cos²θ - cos⁴θ)    b) 75.5º

Explanation:

a) For this exercise we must use Malus's law

         I = I₀ cos² θ

where tea is the angle between the two polarizers.

We apply this expression to our case

* Polarizer 1 suppose that it is vertical and polarizer 2 (intermediate) is at an angle θ with respect to the vertical

         I₁ = I₀ cos² θ

* We analyze for the polarity 2 and the last polarizer 3 which indicate that it must be at 90º from the first one, therefore it must be horizontal.

The angle of polarizers 2 and 3 is θ' measured from the horizontal, if we measure with respect to the vertical

              θ₂ = 90- θ’ = θ

fiate that in the exercise we must take a reference system and measure everything with respect to this system.

          I = I₁ cos² θ'

we substitute

         I = (I₀ cos² tea) cos² (θ - 90)

        cos (θ -90) = cos θ cos 90 + sin θ sin 90 = sin θ

         I = Io cos² θ sin² θ

        1= cos²θ+ sin²θ

       sin²θ = 1 - cos²θ

        I= I₀ (cos²θ - cos⁴θ)

b) to find when the intensity is maximum,

we can use that we have an extreme point when the drift is zero

          [tex]\frac{dI}{d \theta}[/tex] = 0

          \frac{dI}{d \theta}= Io (2 cos θ - 4 cos³θ) = 0

whereby

            cos θ - 2 cos³ θ = 0

            cos θ ( 1 - 2 cos² θ) = 0  

The zeros of this function are in

           θ = 90º

           1-2cos²θ =0       cos θ = 0.25  θ =  75.5º

Let's analyze this two results for the angle of 90º the intnesidd is zero with respect to the first polarizer, so it is not an acceptable solution.

Consequently, the angle that allows the maximum intensity to pass is 75.5º

Answer:

1.) 10.61 A

2.) 0.27 A

Explanation:

Given that a sinusoidal A.C has a maximum value of 15A.

1) What are its r.m.s values?

ii) If the time is recorded from the instant the current is zero and is becoming

positive, what is the instantaneous value of the current after 1/300s, given the

frequency is 50 Hz.​

Solution.

1.)

The r.m.s current = peak current/root 2

The r.m.s current = 0.7071 × 15

The r.m.s current = 10.61 A

2.)

Given that

Time = 1/300 s

Frequency = 50 Hz

Instantaneous current can be calculated by using the formula

I = I sin wt

Where w = 2πf

Instantaneous current = 15( sin 2πft)

I = 15 × sin ( 2 × 3.143 × 50 × 1/300 )

I = 15 × sin ( 1.047 )

I = 15 × 0.01827

I = 0.27 A

Therefore, the instantaneous current is 0.27A

From the diagram, the fossil of fish is considered the oldest fossil. Because the oldest fossils are formed at the bottom whereas the others are at the top of the soil.

When living organisms like plants, animals, and human beings are died, their  bodies get buried in the form of sediments in the sand, rock water bodies, etc..,

It also includes the preserved remains of life for more than 10,000 years. It is the preserved remains, sediments, and impressions to trace the life of the organisms and their behavior.

When living organisms died and are buried in sand or mud, the tissues of living organisms get decomposed leaving the bones which is harder. After the organisms are buried in the sand or mud, several sediments, and sand was built over the top of the buried organisms.

These sand and sediments over the buried organisms eventually form the layer of rocks. This is how fossils are made and these fossils were identified when the rocks were broken or by cause of soil erosion.

The age of the fossils was identified by the stacks of layered rocks with the help of the superposition principle. The oldest fossils are present at the bottom of the rocks whereas the youngest fossils are present at the top of the rocks. This process is called Relative dating.

Hence, from the given diagram the fossil of fish is present at the bottom of the rock unlike the others fossils like monkeys and lizard. Thus, the oldest fossil is fish and the youngest one is a monkey.

To learn more about the Fossils:

https://brainly.com/question/31419516

#SPJ2

Answer:

DNA ligase

Explanation:

DNA Ligase is the enzyme that binds fragments of DNA together by forming two phosphodiester bonds between the 3' hydroxyl end of one nucleotide with the 5' phosphate end of the other. This reaction requires the hydrolysis of ATP.

cold, dry, and stable air masses .

Answer:

i think is c

Explanation:

Answer:

C

Explanation:

C makes more sense than D, Because it says the minimum value is when it stays at rest.

Answer:

2000 N.

Explanation:

From the question given above, the following data were obtained:

Load (L) = 8000 N

Mechanical advantage (MA) = 4

Effort (E) =?

The mechanical advantage of a machine is simply defined as:

Mechanical advantage = Load / Effort

MA = L / E

With the above formula, we can obtain the effort used to raise the load of 8000 N as follow:

Load (L) = 8000 N

Mechanical advantage (MA) = 4

Effort (E) =?

MA = L / E

4 = 8000 / E

Cross multiply

4 × E = 8000

Divide both side by 4

E = 8000 / 4

E = 2000 N

Thus, the effort used to raised the load is 2000 N.

Answer:

Option D: 1

Explanation:

The chemical equation given is;

2NaCl = 2Na + XCl2

We want to find the value of X.

On the left hand side, we can see we have 2 moles of both Na and Cl.

On the right hand side, we can see that we have 2 moles of Na and also 2 moles of Cl. Thus, the equation is balanced and as such X = 1

Answer:the wave lengths are shorter and faster

Explanation:

Plato

Answer:

The first answer is correct.  All of the other options include sound, which travels by material force, and can not be transmitted in a vacuum.  Infra-red, radio, and microwaves are all different frequencies of light, and can thus travel through a vacuum.

Answer:

100 milliliters

Explanation:

Explanation:

When there is a high frequency sound the speed of the vibrations is faster and makes a high pitch sound. When there is a low frequency sound the speed of the vibrations is slower and makes a lower pitch sound.

Hmmmm, you either tell your parent, try to fix it, or blame it on the dog with a baseball bat that always comes on your yard and tries to eat you.

o(*￣▽￣*)ブ

Answer:

[tex]0.629\ \text{rad/s}^2[/tex] counterclockwise

[tex]9.98\ \text{s}[/tex]

Explanation:

[tex]r_1[/tex] = Small drive wheel radius = 2.2 cm

[tex]\alpha_1[/tex] = Angular acceleration of the small drive wheel = [tex]8\ \text{rad/s}^2[/tex]

[tex]r_2[/tex] = Radius of pottery wheel = 28 cm

[tex]\alpha_2[/tex] = Angular acceleration of pottery wheel

As the linear acceleration of the system is conserved we have

[tex]r_1\alpha_1=r_2\alpha_2\\\Rightarrow \alpha_2=\dfrac{r_1\alpha_1}{r_2}\\\Rightarrow \alpha_2=\dfrac{2.2\times 8}{28}\\\Rightarrow \alpha_2=0.629\ \text{rad/s}^2[/tex]

The angular acceleration of the pottery wheel is [tex]0.629\ \text{rad/s}^2[/tex].

The rubber drive wheel is rotating in clockwise direction so the pottery wheel will rotate counterclockwise.

[tex]\omega_i[/tex] = Initial angular velocity = 0

[tex]\omega_f[/tex] = Final angular velocity = [tex]60\ \text{rpm}\times \dfrac{2\pi}{60}=6.28\ \text{rad/s}[/tex]

t = Time taken

From the kinematic equations of linear motion we have

[tex]\omega_f=\omega_i+\alpha_2t\\\Rightarrow t=\dfrac{\omega_f-\omega_i}{\alpha_2}\\\Rightarrow t=\dfrac{6.28-0}{0.629}\\\Rightarrow t=9.98\ \text{s}[/tex]

The time it takes the pottery wheel to reach the required speed is [tex]9.98\ \text{s}[/tex]

Answer:

Drink water

Make your find fresh by doing the stuff you love too ❤️

Answer:

406850000 J

Explanation:

From the question

Q = cm...................... Equation 1

Where Q = Amount of heat, c = latent heat of water, m = mass of water

Given: c = 813700 J/g, m = 500 grams

Substitute these values into equation 1

Q = 500×813700

Q = 406850000 J

Hence the amount of heat requires to boil water at 100°C = 406850000 J

Answer:

a) 2250 J

b) 0 J

c) 2250 J

Explanation:

a) Since, the process is isochoric

the change in internal energy

[tex]\Delta U = n C_v(T_f-T_i)[/tex]

Here, n = 0.2 moles

Cv = 12.5 J/mole.K

We have to find T_f so we can use gas equation as

[tex]\frac{P_1V_1}{P_2V_2} =\frac{T_i}{T_f}\\Since, V_1=V_2 [isochoric/process]\\\Rightarrow \frac{P_{atm}}{4P_{atm}} = \frac{300}{T_f} \\\Rightarrow T_f = 1200 K[/tex]

So,  [tex]\Delta U= 0.2\times12.5(1200-300)\\=2250 J[/tex]

b) Since, the process is isochoric no work shall be done.

c) By first law of thermodynamics we have

[tex]\Delta U = Q-W\\Since, W = 0\\\Delta U = Q\\Therefore, Q = 2250 J[/tex]

Since, Q is positive 2250 J of heat will flow into the system.

for sure thermometers and pryometers as I just learned and did some search ing. so these are. two classes of the heat measure measurement s! your welcomes!!

you can probably find out more of this and other stuff on here for more information scientificamerican

Answer:

They would likely do a whole series of dynamic stretches

Explanation:

It would include warming up the body and then dynamically stretching the lower body, and some upper body as well. This isn't a question with one specific answer

Answer:

[tex]5.896\times 10^{-7}\ \text{m}[/tex]

Explanation:

D = Distance of the screen from the light source = 2.2 m

d = Distance between slits = 0.46 mm

m = Order

Distance between adjacent bright fringes is 2.82 m

[tex]y_{m+1}-y_m=2.82\ \text{mm}\\\Rightarrow \dfrac{D(m+1)\lambda}{d}-\dfrac{Dm\lambda}{d}=2.82\times 10^{-3}\\\Rightarrow \dfrac{D\lambda}{d}(m+1-m)=2.82\times 10^{-3}\\\Rightarrow \lambda=\dfrac{d}{D}2.82\times 10^{-3}\\\Rightarrow \lambda=\dfrac{0.46\times 10^{-3}\times 2.82\times 10^{-3}}{2.2}\\\Rightarrow \lambda=5.896\times 10^{-7}\ \text{m}[/tex]

The wavelength of the light that falls on the slits is [tex]5.896\times 10^{-7}\ \text{m}[/tex].

Answer:

   v₀ = 60.38 mi / h

With this stopping distance, the starting speed should have been 60.38 mi/h, which is much higher than the maximum speed allowed.

Explanation:

For this exercise let's start by using Newton's second law

Y axis

        N-W = 0

        N = W

X axis

         fr = m a

the expression for the friction force is

         fr = μ N

we substitute

        μ mg = m a

        μ g = a

calculate us

         a = 0.620  9.8

         a = 6.076 m / s²

now we can use the kinematics relations

          v² = v₀² - 2 a x

suppose v = 0

          v₀ = [tex]\sqrt{2ax}[/tex]Ra 2ax

let's calculate

         v₀ = [tex]\sqrt{2 \ 6076 \ 60}[/tex]

         v₀ = 27.00 m / s

let's slow down to the english system

          v₀ = 27.0 m / s (3.28 ft / 1m) (1 mile / 5280 ft) (3600s / 1h)

          v₀ = 60.38 mi / h

With this stopping distance, the starting speed should have been 60.38 mi/h, which is much higher than the maximum speed allowed.

Answer:

-40 degrees

Explanation:

I just took the Temperature Quiz and got it right. :)

Answer:

LEKWKKAKDJFKWNFKWFF

Explanation:

INLOVE THE WORDS U USE THERE

Answer:

The acceleration of an object depends directly upon the net force acting upon the object, and inversely upon the mass of the object. As the force acting upon an object is increased, the acceleration of the object is increased. As the mass of an object is increased, the acceleration of the object is decreased.

Explanation:

hope it helps pls give me brainless

Answer:

A. I = V / R = 12 / 252 = .048 amps

V = I * R = .048 * 252 = 12 V

V is also the reading the voltage across the battery (12 Volts)